Information processing method, apparatus, and communications device

ABSTRACT

This application discloses an encoding method, an apparatus, a communications device, and a communications system. The method includes: encoding an input bit sequence by using a low density parity check LDPC matrix, where the LDPC matrix is obtained based on a lifting factor Z and a base matrix, and the base matrix includes a row 0 to a row 4 and a column 0 to a column 26 in one of matrices shown in FIG.  3   b - 1 A to FIG.  3   b - 8 B, or the base matrix includes a row 0 to a row 4 and some of a column 0 to a column 26 in one of matrices shown in FIG.  3   b - 1 A to FIG.  3   b - 8 B. According to the encoding method, the apparatus, the communications device, and the communications system, channel coding requirements can be met.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of International Application No.PCT/CN2018/092974, filed on Jun. 27, 2018, which claims priority toChinese Patent Application No. 201710502721.6, filed on Jun. 27, 2017.The disclosures of the aforementioned applications are herebyincorporated by reference in their entireties.

TECHNICAL FIELD

Embodiments of the present application relate to the communicationsfield, and in particular, to an information processing method and acommunications apparatus.

BACKGROUND

A low density parity check (LDPC) code is a type of linear block codingwith a sparse check matrix, and is characterized by a flexible structureand low decoding complexity. Because the LDPC code uses partiallyparallel iterative decoding algorithms, the LDPC code has a higherthroughput than a conventional Turbo code. The LDPC code may be used asan error-correcting code in a communications system, to improve channeltransmission reliability and power utilization. The LDPC codes mayfurther be widely applied to a space communication system, an opticalfiber communication system, a personal communications system, ADSL, amagnetic recording device, and the like. Currently, the LDPC code hasbeen considered as one of channel coding schemes in the 5th generationmobile communications.

In an actual using process, an LDPC matrix having a special structuremay be used. The LDPC matrix H having the special structure may beobtained by lifting an LDPC base matrix having a quasi cycle (QC)structure. A QC-LDPC is suitable for hardware with high parallelism, andprovides a higher throughput. The LDPC matrix can be applied to channelcoding by designing the LDPC matrix.

A QC-LDPC is suitable for hardware with high parallelism, and provides ahigher throughput. The LDPC matrix can be applied to channel coding bydesigning the LDPC matrix.

SUMMARY

Embodiments of the present application provide an information processingmethod, a communications apparatus, and a communications system, tosupport encoding and decoding of information bit sequences of aplurality of lengths.

According to a first aspect, an encoding method and an encoder areprovided. The encoder encodes an input sequence by using a low densityparity check (LDPC) matrix.

According to a second aspect, a decoding method and a decoder areprovided. The decoder decodes an input sequence by using a LDPC matrix.

In one embodiment of the first aspect or the second aspect, the LDPCmatrix is obtained based on a lifting factor Z and a base matrix.

Based on the foregoing embodiment, a base matrix of a base graph 30 amay include a row 0 to a row 4 and a column 0 to a column 26 in one ofmatrices 30 b-10, 30 b-20, 30 b-30, 30 b-40, 30 b-50, 30 b-60, 30 b-70,and 30 b-80; or the base matrix includes a row 0 to a row 4 and some ofa column 0 to a column 26 in one of matrices 30 b-10, 30 b-20, 30 b-30,30 b-40, 30 b-50, 30 b-60, 30 b-70, and 30 b-80; or the base matrix maybe a matrix obtained by performing a row/column transform on a row 0 toa row 4 and a column 0 to a column 26 in one of matrices 30 b-10 to 30b-80; or the base matrix may be a matrix obtained by performing arow/column transform on a row 0 to a row 4 and some of a column 0 to acolumn 26 in one of matrices 30 b-10, 30 b-20, 30 b-30, 30 b-40, 30b-50, 30 b-60, 30 b-70, and 30 b-80.

Further, the base matrix of the base graph 30 a may further include therow 0 to a row (m−1) and the column 0 to a column (n−1) in one of thematrices 30 b-10, 30 b-20, 30 b-30, 30 b-40, 30 b-50, 30 b-60, 30 b-70,and 30 b-80; or the base matrix may be a matrix obtained by performing arow/column transform on the row 0 to a row (m−1) and the column 0 to acolumn (n−1) in one of the matrices 30 b-10, 30 b-20, 30 b-30, 30 b-40,30 b-50, 30 b-60, 30 b-70, and 30 b-80, where 5≤m≤46 and 27≤n≤68.

To support different block lengths, different lifting factors Z arerequired for an LDPC code. Based on the foregoing embodiment, basematrices corresponding to the different lifting factors Z are used basedon the different lifting factors Z. For example, Z=a×2^(j), 0≤j<7, anda∈{2, 3, 5, 7, 9, 11, 13, 15}.

If a=2, the base matrix may include a row 0 to a row 4 and a column 0 toa column 26 in the matrix 30 b-10, or the base matrix includes a row 0to a row 4 and some of a column 0 to a column 26 in the matrix 30 b-10.Further, the base matrix further includes the row 0 to a row (m−1) andthe column 0 to a column (n−1) in the matrix 30 b-10.

If a=3, the base matrix may include a row 0 to a row 4 and a column 0 toa column 26 in the matrix 30 b-20, or the base matrix includes a row 0to a row 4 and some of a column 0 to a column 26 in the matrix 30 b-201. Further, the base matrix further includes the row 0 to a row (m−1)and the column 0 to a column (n−1) in the matrix 30 b-20.

If a=5, the base matrix may include a row 0 to a row 4 and a column 0 toa column 26 in the matrix 30 b-30, or the base matrix includes a row 0to a row 4 and some of a column 0 to a column 26 in the matrix 30 b-30.Further, the base matrix further includes the row 0 to a row (m−1) andthe column 0 to a column (n−1) in the matrix 30 b-30.

If a=7, the base matrix may include a row 0 to a row 4 and a column 0 toa column 26 in the matrix 30 b-40, or the base matrix includes a row 0to a row 4 and some of a column 0 to a column 26 in the matrix 30 b-40.Further, the base matrix further includes the row 0 to a row (m−1) andthe column 0 to a column (n−1) in the matrix 30 b-40.

If a=9, the base matrix may include a row 0 to a row 4 and a column 0 toa column 26 in the matrix 30 b-50, or the base matrix includes a row 0to a row 4 and some of a column 0 to a column 26 in the matrix 30 b-50.Further, the base matrix further includes the row 0 to a row (m−1) andthe column 0 to a column (n−1) in the matrix 30 b-50.

If a=11, the base matrix may include a row 0 to a row 4 and a column 0to a column 26 in the matrix 30 b-60, or the base matrix includes a row0 to a row 4 and some of a column 0 to a column 26 in the matrix 30b-60. Further, the base matrix further includes the row 0 to a row (m−1)and the column 0 to a column (n−1) in the matrix 30 b-60.

If a=13, the base matrix may include a row 0 to a row 4 and a column 0to a column 26 in the matrix 30 b-70, or the base matrix includes a row0 to a row 4 and some of a column 0 to a column 26 in the matrix 30b-70. Further, the base matrix further includes the row 0 to a row (m−1)and the column 0 to a column (n−1) in the matrix 30 b-70.

If a=15, the base matrix may include a row 0 to a row 4 and a column 0to a column 26 in the matrix 30 b-80, or the base matrix includes a row0 to a row 4 and some of a column 0 to a column 26 in the matrix 30b-80. Further, the base matrix further includes the row 0 to a row (m−1)and the column 0 to a column (n−1) in the matrix 30 b-80.

The base matrix may be a matrix obtained by performing a row/columntransform on a corresponding matrix.

Further, in one embodiment, the LDPC matrix may be obtained based on thelifting factor Z and a matrix Hs that is obtained by compensating eachof the foregoing base matrices, or may be obtained based on the liftingfactor Z and a matrix that is obtained by performing a row/columntransform on a matrix Hs obtained by compensating each of the foregoingbase matrices. The compensating each of the foregoing base matrices maybe increasing or decreasing, by an offset, a shift value that is greaterthan or equal to 0 and that corresponds to an element in one or morecolumns of the matrix.

The base graph and the base matrix of the LDPC matrix in the foregoingembodiment can meet performance requirements for code blocks of aplurality of block lengths.

Based on any one of the foregoing aspects or the possible embodiments ofthe aspects, in another possible embodiment, the encoding method furtherincludes: determining the lifting factor Z. For example, a value of thelifting factor Z is determined based on a length K of the inputsequence. In a supported lifting factor set, a minimum Z₀ may be foundand used as the value of the lifting factor Z, and Kb·Z₀≥K is met. Inone embodiment, Kb may be a quantity of information bit columns in thebase matrix of the LDPC code. For example, in the base graph 30 a,Kb=22. In another embodiment, a value of Kb may alternatively vary witha value of K, but does not exceed a quantity of information bit columnsin the base matrix of the LDPC code. For example, when K is greater thana first threshold, Kb=22; or when K is less than or equal to a firstthreshold, and Kb=21. Alternatively, when K is greater than a firstthreshold, Kb=22; when K is less than or equal to a first threshold, andK is greater than a second threshold, Kb=21; or when K is less than orequal to a second threshold, Kb=20.

The lifting factor Z may be determined by the encoder or the decoderbased on the length K of the input sequence, or may be determined byanother device and then provided as an input parameter to the encoder orthe decoder.

In one embodiment, the LDPC matrix may be obtained based on the obtainedlifting factor Z and a base matrix corresponding to the lifting factorZ.

In one embodiment of the first aspect or the second aspect, the LDPCmatrix is obtained based on the lifting factor Z and parameters of theLDPC base matrix.

The parameters of the LDPC matrix may include a row index, columns inwhich non-zero elements are located, and shift values of the non-zeroelements, and are saved in forms of Table 3-10, Table 3-20, Table 3-30,Table 3-40, Table 3-50, Table 3-60, Table 3-70, and Table 3-80. A rowweight may further be included. Each of position in the columns in whichthe non-zero elements are located is in a one-to-one correspondence witheach of the shift values of the non-zero elements.

In this way, the encoder encodes the input sequence based on the liftingfactor Z and the parameters of the LDPC matrix. Parameters saved inTable 3-10 correspond to the matrix 30 b-10, parameters saved in Table3-20 correspond to the matrix 30 b-20, parameters saved in Table 3-30correspond to the matrix 30 b-30, parameters saved in Table 3-40correspond to the matrix 30 b-40, parameters saved in Table 3-50correspond to the matrix 30 b-50, parameters saved in Table 3-60correspond to the matrix 30 b-60, parameters saved in Table 3-70correspond to the matrix 30 b-70, and parameters saved in Table 3-80correspond to the matrix 30 b-80.

For a communications device at a transmit end, the encoding the inputsequence by using the LDPC matrix may include:

encoding the input sequence by using the LDPC matrix corresponding tothe lifting factor Z; or performing a row/column transform on the LDPCmatrix corresponding to the lifting factor Z, and encoding the inputsequence by using a row/column-transformed matrix. In this application,the row/column transform is a row transform, a column transform, or arow transform and a column transform.

For a communications device at a receive end, the decoding the inputsequence by using the LDPC matrix may include:

decoding the input sequence by using the LDPC matrix corresponding tothe lifting factor Z; or performing a row/column transform on the LDPCmatrix corresponding to the lifting factor Z, and encoding the inputsequence by using a row/column-transformed matrix. In this application,the row/column transform is a row transform, a column transform, or arow transform and a column transform.

In one embodiment, the LDPC matrix may be saved, and the input sequenceis encoded by using the LDPC matrix; or an LDPC matrix that may be usedfor encoding is obtained through transformation (by performing arow/column transform) or lifting based on the LDPC matrix.

In one embodiment, the parameters may be saved, and an LDPC matrix usedfor encoding or decoding may be obtained based on the parameters, sothat the input sequence can be encoded or decoded based on the LDPCmatrix. The parameters include at least one of the following: a basegraph, a base matrix, a transformed matrix obtained by performing arow/column transform based on the base graph or the base matrix, alifting matrix based on the base graph or the base matrix, a shift valueof a non-zero element in the base matrix, or any parameter related toLDPC matrix obtaining.

In one embodiment, the base matrix of the LDPC matrix may be saved in amemory.

In one embodiment, the base graph of the LDPC matrix is saved in amemory, and the shift value of the non-zero element in the base matrixof the LDPC matrix may be saved in the memory.

In one embodiment, the parameters of the LDPC matrix are saved in amemory in forms of Table 3-10 to Table 23-80.

Based on the foregoing embodiments, at least one of a base graph and abase matrix that are used for LDPC encoding or decoding is obtained byperforming row switching, column switching, or row switching and columnswitching on at least one of the base graph and the base matrix of theLDPC matrix.

According to a third aspect, a communications apparatus is provided. Thecommunications apparatus may include corresponding modules configured toperform the foregoing method designs. The modules may be software and/orhardware.

In one embodiment, the communications apparatus provided in the thirdaspect includes a processor and a transceiver component. The processorand the transceiver component may be configured to implement functionsin the foregoing encoding or decoding method. In this design, if thecommunications apparatus is a terminal, a base station, or anothernetwork device, the transceiver component of the communicationsapparatus may be a transceiver. If the communications apparatus is abaseband chip or a baseband processing board, the transceiver componentof the communications apparatus may be an input/output circuit of thebaseband chip or the baseband processing board, and is configured toreceive/send an input/output signal. In one embodiment, thecommunications apparatus may further include a memory, configured tostore data and/or an instruction.

In one embodiment, the processor may include the encoder in the firstaspect and a determining unit. The determining unit is configured todetermine a lifting factor Z required for encoding an input sequence.The encoder is configured to encode the input sequence by using an LDPCmatrix corresponding to the lifting factor Z.

In one embodiment, the processor may include the decoder in the secondaspect and an obtaining unit. The obtaining unit is configured to obtaina soft value of an LDPC code and a lifting factor Z. The decoder isconfigured to decode the soft value of the LDPC code based on a basematrix H_(B) corresponding to the lifting factor Z, to obtain aninformation bit sequence.

According to a fourth aspect, a communications apparatus is provided.The communications apparatus includes one or more processors.

In one embodiment, the one or more processors may implement functions ofthe encoder in the first aspect. In one embodiment, the encoder in thefirst aspect may be a part of the processor. The processor may implementother functions in addition to the functions of the encoder in the firstaspect.

In one embodiment, the one or more processors may implement functions ofthe decoder in the second aspect. In one embodiment, the decoder in thesecond aspect may be a part of the processor.

In one embodiment, the communications apparatus may further include atransceiver and an antenna.

In one embodiment, the communications apparatus may further include adevice configured to generate a transport block CRC, a device configuredto perform code block segmentation and a CRC check, an interleaverconfigured to perform interleaving, a modulator configured to performmodulation processing, or the like.

In one embodiment, the communications apparatus may further include ademodulator configured to perform a demodulation operation, adeinterleaver configured to perform deinterleaving, a device configuredto perform de-rate matching, or the like. Functions of these devices maybe implemented by the one or more processors.

In one embodiment, functions of these devices may be implemented by theone or more processors.

According to a fifth aspect, an embodiment of this application providesa communications system. The system includes the communicationsapparatus in the third aspect.

According to a sixth aspect, an embodiment of the present applicationprovides a communications system. The system includes one or morecommunications apparatuses in the fourth aspect.

According to still another aspect, an embodiment of the presentapplication provides a computer storage medium. The computer storagemedium stores a program, and when the program runs, a computer isenabled to perform the methods in the foregoing aspects.

Yet another aspect of this application provides a computer programproduct including an instruction. When the instruction is run on acomputer, the computer is enabled to perform the methods in theforegoing aspects.

According to the information processing method, the apparatus, thecommunications device, and the communications system in the embodimentsof the present application, a system requirement for flexible codelengths and code rates can be met in terms of encoding performance andan error floor.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a schematic diagram of a base graph and a base matrix of anLDPC code, and a circulant permutation matrix of the base matrix;

FIG. 2 is a schematic structural diagram of a base graph of an LDPCcode;

FIG. 3a -1 and FIG. 3a -2 are a schematic diagram of a base graph of anLDPC code according to an embodiment of the present application;

FIG. 3b -1A and FIG. 3b -1B are a schematic diagram of a base matrixaccording to an embodiment of the present application;

FIG. 3b -2A and FIG. 3b -2B are a schematic diagram of another basematrix according to an embodiment of the present application;

FIG. 3b -3A and FIG. 3b -6B are a schematic diagram of another basematrix according to an embodiment of the present application;

FIG. 3b -4A and FIG. 3b -4B are a schematic diagram of another basematrix according to an embodiment of the present application;

FIG. 3b -5A and FIG. 3b -5B are a schematic diagram of another basematrix according to an embodiment of the present application;

FIG. 3b -6A and FIG. 3b -6B are a schematic diagram of another basematrix according to an embodiment of the present application;

FIG. 3b -7A and FIG. 3b -7B are a schematic diagram of another basematrix according to an embodiment of the present application;

FIG. 3b -8A and FIG. 3b -8B are a schematic diagram of another basematrix according to an embodiment of the present application;

FIG. 4 is a schematic performance diagram according to an embodiment ofthe present application;

FIG. 5 is a flowchart of an information processing method according toanother embodiment of the present application;

FIG. 6 is a flowchart of an information processing method according toanother embodiment of the present application;

FIG. 7 is a schematic structural diagram of an information processingapparatus according to another embodiment of the present application;and

FIG. 8 is a schematic diagram of a communications system according toanother embodiment of the present application.

DESCRIPTION OF EMBODIMENTS

To facilitate understanding, the following describes some nouns in thisapplication.

In this application, nouns “network” and “system” are usuallyinterchangeably used, and “apparatus” and “device” are also usuallyinterchangeably used, but meanings of the nouns can be understood by aperson skilled in the art. A “communications apparatus” may be a chip(such as a baseband chip, a data signal processing chip, or ageneral-purpose chip), a terminal, a base station, or another networkdevice. The terminal is a device having a communication function, andmay include a handheld device, a vehicle-mounted device, a wearabledevice, or a computing device having a wireless communication function,another processing device connected to a wireless modem, or the like.The terminal may have different names in different networks, such asuser equipment, a mobile station, a subscriber unit, a station, acellular phone, a personal digital assistant, a wireless modem, awireless communications device, a handheld device, a laptop computer, acordless phone, and a wireless local loop station. For ease ofdescription, the names are briefly referred to as the terminal in thisapplication. The base station (BS), also referred to as a base stationdevice, is a device deployed in a radio access network to provide awireless communication function. The base station may be different namesin different radio access systems. For example, a base station in auniversal mobile telecommunications system (UMTS) network is referred toas a NodeB, a base station in an LTE network is referred to as anevolved NodeB (eNB or eNodeB), and a base station in a new radio (NR)network is referred to as a transmission reception point (TRP) or anext-generation NodeB (gNB). Alternatively, a base station in anotherevolved network may have another name. This is not limited in thepresent application.

The following describes technical solutions in the embodiments of thepresent application with reference to the accompanying drawings in theembodiments of the present application.

Usually, an LDPC code may be represented by a parity check matrix H. Theparity check matrix H of the LDPC code may be obtained by using a basegraph and a shift value. The base graph may usually include m×n matrixelements (entry), and may be represented by a matrix with m rows and ncolumns. A value of a matrix element is 0 or 1. An element whose valueis 0 is also referred to as a zero element sometimes, indicating thatthe element may be replaced with a Z×Z all-zero matrix. An element whosevalue is 1 is also referred to as a non-zero element sometimes,indicating that the element may be replaced by a Z×Z circulantpermutation matrix. In other words, each matrix element represents oneall-zero matrix or one circulant permutation matrix. 10 a in FIG. 1shows elements in an example base graph of an LDPC code with a QCstructure, where m=5 and n=27. It should be noted that, in thisspecification, row indexes and column indexes of a base graph and amatrix are numbered from 0. This is merely for ease of description. Forexample, a column 0 indicates a first column of the base graph and thematrix, a column 1 indicates a second column of the base graph and thematrix, a row 0 indicates a first row of the base graph and the matrix,and a row 1 indicates a second row of the base graph and the matrix, andso on.

It may be understood that, row indexes and column indexes mayalternatively be numbered from 1, and in this case, row indexes andcolumn indexes shown in this specification are increased by 1 to obtaincorresponding row indexes and column indexes. For example, if the rowindexes or the column indexes are numbered from 1, a column 1 indicatesa first column of the base graph and the matrix, a column 2 indicates asecond column of the base graph and the matrix, a row 1 indicates afirst row of the base graph and the matrix, and a row 2 indicates asecond row of the base graph and the matrix, and so on.

If a value of an element in a row i and a column j of the base graph is1, a shift value of the element is P_(i,j), and P_(i,j) is an integergreater than or equal to 0, it indicates that the element, in the row iand the column j, whose value is 1 may be replaced with a Z×Z circulantpermutation matrix corresponding to P_(i,j). The circulant permutationmatrix may be obtained by performing a right cyclic shift on a Z×Zidentity matrix for P_(i,j) times. It may be learned that, in the basegraph, each element whose value is 0 is replaced with a Z×Z all-zeromatrix, and each element whose value is 1 is replaced with a Z×Zcirculant permutation matrix corresponding to a shift value of theelement, so that the parity check matrix of the LDPC code can beobtained. Z is a positive integer, may also be referred to as a liftingfactor, and may be determined based on a code block size and aninformation data size that are supported by a system. It may be learnedthat the parity check matrix H has a size of (m×Z)×(n×Z). For example,if the lifting factor Z is 4, each zero element is replaced with a 4×4all-zero matrix 11 a. If P_(2, 3)=2, a non-zero element in a row 2 and acolumn 3 is replaced with a 4×4 circulant permutation matrix 11 d, andthe matrix is obtained by performing a right cyclic shift on a 4×4identity matrix 11 b twice. If P_(2, 4)=0, a non-zero element in a row 2and a column 4 is replaced with the identity matrix 11 b. It should benoted that, this is merely an example for description, and the presentapplication is not limited thereto.

Because P_(i,j) may be obtained based on the lifting factor Z, differentP_(i,j) may be obtained by using different lifting factors Z for anelement whose value is 1 in a same position. To simplify implementation,usually, a base matrix with m rows and n columns, also referred to as aPCM (parity check matrix) sometimes, may further be defined in thesystem. Each element in the base matrix is in a one-to-onecorrespondence with a position of each element in the base graph. Aposition of a zero element in the base graph is the same as that of thezero element in the base matrix, and the zero element may be representedby −1 or a null value “null”. A position of the non-zero element, in therow i and the column j in the base graph, whose value is 1 is the sameas that of the non-zero element in the base matrix, and the non-zeroelement may be represented as P_(i,j). P_(i,j) may be a shift valuedefined relative to a predetermined or particular lifting factor Z. Inthe embodiments of this application, the base matrix is also referred toas a shift matrix of the base graph matrix sometimes.

10 b in FIG. 1 shows a base matrix corresponding to a base graph 10 a.

Usually, the base graph or the base matrix of the LDPC code may furtherinclude p built-in puncture bit columns. p may be an integer from 0 to2. These columns are used for encoding, but system bits corresponding tothe columns are not sent, so that a code rate of the base matrix of theLDPC code meets R=(n−m)/(n−p). Using the base graph 10 a as an example,if there are two built-in puncture bit columns, a code rate is(27−5)/(27−2)=0.88, approximating to 8/9.

An LDPC code used in a wireless communications system is a QC-LDPC code.A parity bit part of the LDPC code has a dual-diagonal structure or araptor-like structure. This can make encoding simple, and supportincremental redundancy hybrid retransmission. In a decoder for theQC-LDPC code, a QC-LDPC shift network (QSN), a Banyan network, or aBenes network is usually used to implement a cyclic shift ofinformation.

A base graph of the QC-LDPC code having the raptor-like structure has amatrix size of m rows and n columns, and may include five submatrices:A, B, C, D, and E. A matrix weight is determined by a quantity ofnon-zero elements. A row weight is a quantity of non-zero elementsincluded in a row, a column weight is a quantity of non-zero elementsincluded in a column.

As shown in 200 in FIG. 2, the submatrix A is a matrix with m_(A) rowsand n_(A) columns, and may have a size of m_(A)×n_(A). Each columncorresponds to Z system bits in the LDPC code, and the system bit isalso referred to as an information bit sometimes.

The submatrix B is a square matrix with m_(A) rows and m_(A) columns,and may have a size of m_(A)×m_(A). Each column corresponds to Z paritybits in the LDPC code. The submatrix B includes a submatrix B′ having adual-diagonal structure and one matrix column whose column weight is 3(which is referred to as a column having a column weight of 3 forshort). The matrix column whose column weight is 3 may be located beforethe submatrix B′, as shown in 20 a in FIG. 2. The submatrix B mayfurther include one or more matrix columns whose column weight is 1(which is referred to as a column having a column weight of 1). Forexample, a possible embodiment is shown in 20 b or 20 c in FIG. 2.

Usually, a matrix generated based on the submatrix A and the submatrix Bmay be referred to as a core matrix, and may be used to support highcode-rate encoding.

The submatrix C is an all-zero matrix, and has a size of m_(A)×m_(D).

The submatrix E is an identity matrix, and has a size of m_(D)×m_(D).

The submatrix D has a size of m_(D)×(n_(A)+m_(A)), and may usually beused to generate parity bits of a low code rate.

Because structures of the submatrix C and the submatrix E are relativelyfixed, structures of the submatrix A, the submatrix B, and the submatrixD are one of factors affecting encoding and decoding performance of theLDPC code.

When encoding is performed by using the LDPC matrix having theraptor-like structure, in one embodiment, a matrix including thesubmatrix A and the submatrix B, that is, the core matrix, may beencoded first, to obtain a parity bit corresponding to the submatrix B,and then the entire matrix is encoded, to obtain parity bitscorresponding to the submatrix E. Because the submatrix B may includethe submatrix B′ having the dual-diagonal structure and the columnhaving a column weight of 1, during the encoding, parity bitscorresponding to the dual-diagonal structure may be obtained first, andthen parity bits corresponding to the column having a column weight of 1is obtained.

The following provides an example encoding scheme. It is assumed thatthe core matrix formed by the submatrix A and the submatrix B isH_(core). The last row and the last column are removed from H_(core),that is, a column having a column weight of 1 and a row in which anon-zero element in the column is located are removed from H_(core), toobtain a matrix H_(core-dual). Parity bits in H_(core-dual) arerepresented by H_(e)=[H_(e1) H_(e2)], H_(e1) represents a column havinga column weight of 3, and H_(e2) represents a dual-diagonal structure.According to a definition of the matrix of the LDPC code,H_(core-dual)·[S P_(e)]^(T)=0, where S represents an input sequence andis represented by a vector formed by information bits, P_(e) representsa vector formed by parity bits, and [S P_(e)]^(T) represents a matrixtranspose formed by the input sequence S and P_(e). In this way, theparity bits corresponding to H_(core-dual) may first be calculated basedon the input sequence S and H_(core-dual), where the input sequence Sincludes all information bits; and then the parity bits corresponding tothe column having a column weight of 1 in the submatrix B is calculatedbased on the obtained parity bits corresponding to H_(core-dual) and theinput sequence S. In this case, all parity bits corresponding to thesubmatrix B may be obtained. Next, parity bits corresponding to thesubmatrix E are obtained through encoding by using the submatrix D,based on the input sequence S and the parity bits corresponding to thesubmatrix B, to obtain all information bits and all parity bits. Thesebits form an encoded sequence, that is, an LDPC code sequence.

In one embodiment, encoding LDPC code may further include shortening andpuncturing operations. Neither a shortened bit nor a punctured bit issent.

The shortening is usually performed starting from the last informationbit and goes forward, and may be performed in different manners. Using aquantity so of shortened bits as an example, the last so bits in theinput sequence S may be set to known bits, to obtain an input sequenceS′. For example, the bits are set to 0 or null, or some other values.Then, the input sequence S′ is encoded by using the LDPC matrix. Foranother example, the last (so mod Z) bits in the input sequence S mayalternatively be set to known bits, to obtain an input sequence S′. Forexample, the bits are set to 0 or null, or some other values. The last

$\left\lfloor \frac{s_{0}}{Z} \right\rfloor$columns are deleted from the submatrix A to obtain an LDPC matrix H′,and the input sequence S′ is encoded by using the LDPC matrix H′. Inother words, the last

$\left\lfloor \frac{s_{0}}{Z} \right\rfloor$columns in the submatrix A are not used for encoding the input sequenceS′. After the encoding is completed, the shortened bits are not sent.

The puncturing may be building a puncture bit in the input sequence orpuncturing the parity bit. Usually, a parity bit is also puncturedstarting from the last parity bit. Certainly, the puncturing may beperformed in a puncturing sequence preset in the system. In oneembodiment, an input sequence is first encoded, and then the last pparity bits of parity bits are selected based on a quantity p of bitsthat need to be punctured, or p bits are selected based on thepuncturing sequence preset in the system. The p bits are not sent. Inone embodiment, p columns of a matrix that correspond to punctured bitsand p rows in which non-zero elements in these columns are located mayalternatively be determined. These rows and columns are not used forencoding, and therefore, and no corresponding parity bits are generated.

It should be noted that, the encoding scheme is merely used as anexample herein, and another encoding scheme known to a person skilled inthe art may be used based on the base graph and/or the base matrixprovided in this application. This is not limited in this application.Decoding in this application may be performed in a plurality of encodingschemes such as a min-sum (MS) decoding scheme or a belief propagationdecoding scheme. The MS decoding scheme is also referred to as a floodMS decoding scheme sometimes. For example, an input sequence isinitialized, iteration processing is performed on the initialized inputsequence, hard-decision detection is performed after iteration, and ahard-decision result is checked. If a decoding result meets a checkequation, decoding succeeds, iteration ends, and the decision result isoutput. If a decoding result does not meet a check equation, theiteration processing is performed again before a maximum quantity ofiteration times is reached, and if the check still fails when themaximum quantity of iteration times is reached, decoding fails. It maybe understood that a person skilled in the art may understand aprinciple of MS decoding. Details are not described herein.

It should be noted that, the decoding scheme is merely an example fordescription, another decoding scheme known to a person skilled in theart may be used based on the base graph and/or the base matrix providedin this application. The decoding scheme is not limited in thisapplication.

Usually, an LDPC code may be obtained by designing a base graph or abase matrix. For example, a performance upper limit of the LDPC code maybe determined by performing a density evolution method on the base graphor the base matrix, and an error floor of the LDPC code is determinedbased on a shift value in the base matrix. By designing the base graphor the base matrix, encoding or decoding performance can be improved,and an error floor can be reduced. In a wireless communications system,a code length is flexibly variable. For example, the code length may be2560 bits, 38400 bits, or the like. FIG. 3a -1 and FIG. 3a -2 are anexample of a base graph 30 a of an LDPC code, and FIG. 3b -1A to FIG. 3b-8B are examples of base matrices of the base graph 30 a. The examplesmeet a performance requirement for a plurality of block lengths. Forease of description and understanding, the top side and the left side ofFIG. 3 a-1 and FIG. 3a -2, and FIG. 3b -1A to FIG. 3b -8B respectivelyshow column indexes and row indexes.

FIG. 3a -1 and FIG. 3a -2 shows an example of a base graph 30 a of anLDPC code. In the figure, 0 to 67 (that is, columns 0 to 67) in theuppermost row indicate column indexes, and 0 to 45 (that is, rows 0 to45) in the leftmost column indicate row indexes. In other words, amatrix of the base graph 30 a has a size of 46 rows and 68 columns.

In one embodiment, the submatrix A and the submatrix B may be consideredas the core matrix of the base graph of the LDPC code, and may be usedfor high code-rate encoding. A matrix with 5 rows and 27 columns isformed. For example, a matrix with 5 rows and 27 columns shown in thebase graph 10 a may be used as the core matrix of the base graph.

In one embodiment, the submatrix A may include one or more built-inpuncture bit columns, for example, may include two built-in puncture bitcolumns. In this case, after puncturing, a code rate that can besupported by the core matrix is 0.88.

The submatrix B may include one column having a column weight of 3, thatis, a column weight of a column 0 of the submatrix B (a column 22 of thecore matrix) is 3. A column 1 to a column 3 of the submatrix B (a column23 to a column 25 of the core matrix) and a row 0 to a row 3 of thesubmatrix B are a dual-diagonal structure. The submatrix B furtherincludes one column having a column weight of 1 (a column 26 of the corematrix).

In one embodiment, the submatrix A may correspond to system bits, alsoreferred to as information bits sometimes, has a size of m_(A) rows and22 columns, where m_(A)=5, and includes elements in a row 0 to a row 4and a column 0 to a column 21 in the base graph 30 a.

In one embodiment, the submatrix B may correspond to parity bits, has asize of m_(A) rows and m_(A) columns, and includes elements in a row 0to a row 4 and a column 22 to a column 26 in the base graph 30 a.

To obtain a flexible code rate, a submatrix C, a submatrix D, and asubmatrix E of corresponding sizes may be added based on a core matrix,to obtain different code rates. The submatrix C is an all-zero matrix,and the submatrix is an identity matrix. The sizes of the submatrix Cand the submatrix D are mainly determined based on the code rate, andthe submatrix C and the submatrix D have a relatively fixed structure.The core matrix and the submatrix D mainly affect encoding and decodingperformance. Rows and columns are added based on the core matrix to formcorresponding C, D, and E, so that different code rates can be obtained.

A quantity m_(D) of columns of the submatrix D is a sum of quantities ofcolumns of the submatrix A and the submatrix B, and a quantity of rowsin the submatrix D is mainly related to a code rate. Using the basegraph 30 a as an example, a quantity of columns in the submatrix D is27. If the code rate supported by the LDPC code is R_(m), the base graphor the base matrix of the LDPC code has a size of m rows and n columns,where n=n_(A)/R_(m)+p and m=n−n_(A)=n_(A)/R_(m)+p−n_(A). If a minimumcode rate R_(m) is 1/3, and a quantity p of built-in puncture columns is2, using the base graph 30 a as an example, n=68 and m=46. A maximumquantity m_(D) of rows in the submatrix D may be m−m_(A)=46−5=41, andtherefore, 0≤m_(D)≤41.

Using the base graph 30 a as an example, the submatrix D may includem_(D) rows of a row 5 to a row 41 in the base graph 30 a.

In this application, if there is a maximum of only one non-zero elementin two adjacent rows in a same column in a base graph, the two rows aremutually orthogonal. If a maximum of only one non-zero element exists ina same column in columns other than some columns in two adjacent rows inthe base graph, the two adjacent rows are quasi-orthogonal. For example,there is only one non-zero element in a column other than a built-inpunctured bit column in the two adjacent rows, and it may be consideredthat the two adjacent rows are quasi-orthogonal.

The row 5 to the row 41 in the base graph 30 a may include a pluralityof quasi-orthogonal rows and at least two orthogonal rows. For example,the row 5 to the row 41 in the base graph 30 a include at least 15 rowsmeeting the quasi-orthogonal structure, and there is a maximum of onlyone non-zero element in a same column in columns other than the built-inpunctured bit column in any two adjacent rows of the 15 rows. The row 5to the row 41 in the base graph 30 a may further include 10 to 26 rowsmeeting the orthogonal structure. In other words, in these rows, thereis a maximum of only one non-zero element in a same column in any twoadjacent rows, that is, there is also a maximum of only one non-zeroelement in the built-in punctured bit column.

If m_(D)=15, the submatrix D in the base graph of the LDPC code has asize of 15 rows and 27 columns. The submatrix D may be a matrix formedby a row 5 to a row 19 and a column 0 to a column 26 in the base graph30 a. A corresponding code rate supported by the LDPC code is22/40=0.55. At this code rate, the base graph of the LDPC codecorresponds to a matrix formed by a row 0 and a row 19 and a column 0 toa column 41 in the base graph 30 a. The submatrix E is an identitymatrix with 15 rows and 15 columns, and the submatrix C is an all-zeromatrix with five rows and 15 columns.

If m_(D)=19, the submatrix D in the base graph of the LDPC code has asize of 19 rows and 27 columns. The submatrix D may be a matrix formedby a row 5 to a row 23 and a column 0 to a column 26 in the base graph30 a. A corresponding code rate supported by the LDPC code is 22/44=1/2.At this code rate, the base graph of the LDPC code corresponds to amatrix formed by a row 0 and a row 23 and a column 0 to a column 45 inthe base graph 30 a. The submatrix E is an identity matrix with 19 rowsand 19 columns, and the submatrix C is an all-zero matrix with five rowsand 19 columns.

The rest can be deduced by analogy. Details are not described one by oneherein again.

In a design, row/column switching may be performed on the base graphand/or the base matrix, that is, row switching, column switching, or rowswitching and column switching are performed. The row/column switchingoperation does not change any row weight or column weight, and aquantity of non-zero elements does not change either. Therefore, a basegraph and/or a base matrix obtained through row/column switchinghave/has limited impact on system performance. In other words, on thewhole, impact on the system performance is acceptable and fall within atolerable range. For example, the performance deteriorates in anallowable range in some scenarios or in some ranges. However, theperformance is improved in some scenarios or in some ranges. On thewhole, there is little impact on the performance.

For example, in the base graph 30 a, a row 34 may be switched with a row36, and a column 44 may be switched with a column 45. For anotherexample, the submatrix D includes m_(D) rows in a matrix F. The m_(D)rows may not be switched with each other, or one or more of the rows maybe switched, and the submatrix E is still of a diagonal structure andneither row switching nor column switching is performed in the submatrixE. For example, a row 27 is switched with a row 29 in the matrix F. Thesubmatrix D includes the m_(D) rows in the matrix F, and the submatrix Eis still of a diagonal structure. It may be understood that, if the basegraph or the base matrix includes the submatrix D, when columns in thecore matrix are switched, corresponding columns in the submatrix D alsoneed to be switched.

As shown in FIG. 3b -1A to FIG. 3b -8B, matrices 30 b-10 to 30 b-80 aredesigns of a plurality of base matrices of the base graph 30 a. Alocation of a non-zero element in a row i and a column j in the basegraph 30 a is the same as that of the non-zero element in each of thematrices 30 b-10 to 30 b-80. A value of the non-zero element is a shiftvalue V_(i,j), and a zero element is represented as −1 or null in ashift matrix. A part corresponding to the submatrix D in the base matrixmay include m_(D) rows of a row 5 to a row 45 in any base matrix, and avalue of m_(D) may be selected based on different code rates. It may beunderstood that, if the base graph is a matrix obtained by performing arow/column transform relative to base graph 30 a, the base matrix isalso a matrix obtained by performing a row/column transform relative toany one of the matrices 30 b-10 to 30 b-80 correspondingly.

In one embodiment, the base matrix of the LDPC code may include a row 0to a row 4 and a column 0 to a column 26 in any one of the matrices 30b-10 to 30 b-80 shown in FIG. 3b -1A to FIG. 3b -8B. In this case, amatrix formed by a row 0 to a row 4 and a column 0 to a column 26 in anyone of the matrices shown in FIG. 3b -1A to FIG. 3b -8B may be used as acore part of the base matrix. In this design, other parts of the basematrix of the LDPC code, for example, the matrix C, D, and E, do nothave limited structures, for example, may be of any structure shown inFIG. 3b -1A to FIG. 3b -8B, or may use other matrix designs.

In one embodiment, the base matrix of the LDPC code may include a matrixformed by a row 0 to a row (m−1) and a column 0 to a column (n−1) in anyone of the matrices 30 b-10 to 30 b-80 shown in FIG. 3b -1A to FIG. 3b-8B, where 5≤m≤46, m is an integer, 27≤n≤68, and n is an integer.

In this embodiment, other parts of the base matrix of the LDPC code donot have limited structures, for example, may have any structure shownin FIG. 3b -1A to FIG. 3b -8B, or may use other matrix designs.

In one embodiment, the base matrix of the LDPC code may include a matrixformed by a row 0 to a row 4 and some of a column 0 to a column 26 inany one of the matrices 30 b-10 to 30 b-80 shown in FIG. 3b -1A to FIG.3b -8B. For example, core parts (the row 0 to the row 4 and the column 0to the column 26) of the matrices shown in FIG. 3b -1A to FIG. 3b -8Bmay be shortened and/or punctured. In one embodiment, the base matrix ofthe LDPC code may not include columns corresponding to shorten and/orpunctured bits.

In this design, other parts of the base matrix of the LDPC code are notlimited, for example, may have structures shown in FIG. 3b -1A to FIG.3b -8B, or may have other structures.

In one embodiment, the base matrix of the LDPC code may include a matrixformed by a row 0 to a row (m−1) and some of a column 0 to a column(n−1) in any one of the matrices 30 b-10 to 30 b-80 shown in FIG. 3b -1Ato FIG. 3b -8B, where 5≤m≤46, m is an integer, 27≤n≤68, and n is aninteger. For example, the row 0 to the row (m−1) and the column 0 to thecolumn (n−1) in any one of the matrices 30 b-10 to 30 b-80 shown in FIG.3b -1A to FIG. 3b -8B may be shortened (shortening) and/or punctured(puncturing). In one embodiment, the base matrix of the LDPC code maynot include columns corresponding to shorten and/or punctured bits. Inthis design, other parts of the base matrix of the LDPC code are notlimited, for example, may have structures shown in FIG. 3b -1A to FIG.3b -8B, or may have other structures.

In one embodiment, the shortening operation may be shortening aninformation bit. Using any one of the matrices shown in FIG. 3b -1A toFIG. 3b -8B as an example, one or more columns of columns 0 to 21 areshortened, so that the base matrix of the LDPC code may not include theone or more shortened columns in any one of the matrices shown in FIG.3b -1A to FIG. 3b -8B. For example, if the column 21 is shortened, thebase matrix of the LDPC code may include: the columns 0 to 20 andcolumns 22 to 26 in any one of matrices 30 b-10 to 30 b-80. For the row0 to the row 4, the column 0 to the column 20, and the column 22 to thecolumn 26, a code rate is 7/8.

In one embodiment, the puncturing may be puncturing a parity bit. Usingany one of the matrices shown in FIG. 3b -1A to FIG. 3b -8B as anexample, one or more of the column 22 to the column 26 are punctured. Inthis case, the base matrix of the LDPC code may not include one or moreof punctured columns in any one of the matrices shown in FIG. 3b -1A toFIG. 3b -8B. For example, if the column 26 is punctured, the base matrixof the LDPC code may include the column 0 to the column 25 in any one ofthe matrices 30 b-10 to 30 b-80.

Different lifting factors Z are designed for the LDPC code, to supportinformation bit sequences of different lengths. In one embodiment,different base matrices may be used for the different lifting factors,to obtain better performance. For example, the lifting factor z=a×2^(j),0≤j<7, and a {2, 3, 5, 7, 9, 11, 13, 15}. Table 1 is a possiblesupported lifting factor set {2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13,14, 15, 16, 18, 20, 22, 24, 26, 28, 30, 32, 36, 40, 44, 48, 52, 56, 60,64, 72, 80, 88, 96, 104, 112, 120, 128, 144, 160, 176, 192, 208, 224,240, 256, 288, 320, 352, 384}. Other than the uppermost row and theleftmost column, each cell indicates a value of Z corresponding tovalues of a and j. For example, when a=2 and j=1, Z=4. For anotherexample, when a=11 and j=3, Z=88. The rest can be deduced by analogy.Details are not described again.

TABLE 1 Z a = 2 a = 3 a = 5 a = 7 a = 9 a = 11 a = 13 a = 15 j = 0 2 3 57 9 11 13 15 j = 1 4 6 10 14 18 22 26 30 j = 2 8 12 20 28 36 44 52 60 j= 3 16 24 40 56 72 88 104 120 j = 4 32 48 80 112 144 176 208 240 j = 564 96 160 224 288 352 j = 6 128 192 320 j = 7 256 384

The lifting factor set supported by the base graph may include all orsome of lifting factors in Table 1. For example, the lifting factor setmay be {24, 26, 28, 30, 32, 36, 40, 44, 48, 52, 56, 60, 64, 72, 80, 88,96, 104, 112, 120, 128, 144, 160, 176, 192, 208, 224, 240, 256, 288,320, 352, 384}, that is, Z is greater than or equal to 24. For anotherexample, the lifting factor set may be a union set of one or more of {2,3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 18, 20, 22} and {24,26, 28, 30, 32, 36, 40, 44, 48, 52, 56, 60, 64, 72, 80, 88, 96, 104,112, 120, 128, 144, 160, 176, 192, 208, 224, 240, 256, 288, 320, 352,384}. It should be noted that this is merely an example herein. Thelifting factor set supported by the base graph may be divided intodifferent subsets based on a value of a. For example, if a=2, a subsetof the lifting factor Z may include one or more of {2, 4, 8, 16, 32, 64,128, 256}. For another example, if a=3, a subset of the lifting factor Zmay include one or more of {3, 6, 12, 24, 48, 96, 192, 384}. The restcan be deduced by analogy.

The lifting factor set supported by the base graph may be divided basedon different values of a, to determine a corresponding base matrix.

If a=2, or when a value of the lifting factor Z is one of {2, 4, 8, 16,32, 64, 128, 256}, the base matrix may include a row 0 to a row 4 and acolumn 0 to a column 26 in the matrix 30 b-10; or the base matrixincludes a row 0 to a row (m−1) and a column 0 to a column (n−1) in thematrix 30 b-10, where 5≤m≤46, m is an integer, 27≤n≤68, and n is aninteger; or the base matrix includes a row 0 to a row (m−1) and some ofa column 0 to a column (n−1) in the matrix 30 b-10, where 5≤m≤46, m isan integer, 27≤n≤68, and n is an integer.

If a=3, or when a value of the lifting factor Z is one of {3, 6, 12, 24,48, 96, 192, 384}, the base matrix may include a row 0 to a row 4 and acolumn 0 to a column 26 in the matrix 30 b-20; or the base matrixincludes a row 0 to a row (m−1) and a column 0 to a column (n−1) in thematrix 30 b-20, where 5≤m≤46, m is an integer, 27≤n≤68, and n is aninteger; or the base matrix includes a row 0 to a row (m−1) and some ofa column 0 to a column (n−1) in the matrix 30 b-20, where 5≤m≤46, m isan integer, 27≤n≤68, and n is an integer.

If a=5, or when a value of the lifting factor Z is one of {5, 10, 20,40, 80, 160, 320}, the base matrix may include a row 0 to a row 4 and acolumn 0 to a column 26 in the matrix 30 b-30; or the base matrixincludes a row 0 to a row (m−1) and a column 0 to a column (n−1) in thematrix 30 b-30, where 5≤m≤46, m is an integer, 27≤n≤68, and n is aninteger; or the base matrix includes a row 0 to a row (m−1) and some ofa column 0 to a column (n−1) in the matrix 30 b-30, where 5≤m≤46, m isan integer, 27≤n≤68, and n is an integer.

If a=7, or when a value of the lifting factor Z is one of {7, 14, 28,56, 112, 224}, the base matrix may include a row 0 to a row 4 and acolumn 0 to a column 26 in the matrix 30 b-40; or the base matrixincludes a row 0 to a row (m−1) and a column 0 to a column (n−1) in thematrix 30 b-40, where 5≤m≤46, m is an integer, 27≤n≤68, and n is aninteger; or the base matrix includes a row 0 to a row (m−1) and some ofa column 0 to a column (n−1) in the matrix 30 b-40, where 5≤m≤46, m isan integer, 27≤n≤68, and n is an integer.

If a=9, or when a value of the lifting factor Z is one of {9, 18, 36,72, 144, 288}, the base matrix may include a row 0 to a row 4 and acolumn 0 to a column 26 in the matrix 30 b-50; or the base matrixincludes a row 0 to a row (m−1) and a column 0 to a column (n−1) in thematrix 30 b-50, where 5≤m≤46, m is an integer, 27≤n≤68, and n is aninteger; or the base matrix includes a row 0 to a row (m−1) and some ofa column 0 to a column (n−1) in the matrix 30 b-50, where 5≤m≤46, m isan integer, 27≤n≤68, and n is an integer.

If a=11, or when a value of the lifting factor Z is one of {11, 22, 44,88, 176, 352}, the base matrix may include a row 0 to a row 4 and acolumn 0 to a column 26 in the matrix 30 b-60; or the base matrixincludes a row 0 to a row (m−1) and a column 0 to a column (n−1) in thematrix 30 b-60, where 5≤m≤46, m is an integer, 27≤n≤68, and n is aninteger; or the base matrix includes a row 0 to a row (m−1) and some ofa column 0 to a column (n−1) in the matrix 30 b-60, where 5≤m≤46, m isan integer, 27≤n≤68, and n is an integer.

If a=13, or when a value of the lifting factor Z is one of {13, 26, 52,104, 208}, the base matrix may include a row 0 to a row 4 and a column 0to a column 26 in the matrix 30 b-70; or the base matrix includes a row0 to a row (m−1) and a column 0 to a column (n−1) in the matrix 30 b-70,where 5≤m≤46, m is an integer, 27≤n≤68, and n is an integer; or the basematrix includes a row 0 to a row (m−1) and some of a column 0 to acolumn (n−1) in the matrix 30 b-70, where 5≤m≤46, m is an integer,27≤n≤68, and n is an integer.

If a=15, or when a value of the lifting factor Z is one of {15, 30, 60,120, 240}, the base matrix may include a row 0 to a row 4 and a column 0to a column 26 in the matrix 30 b-80; or the base matrix includes a row0 to a row (m−1) and a column 0 to a column (n−1) in the matrix 30 b-80,where 5≤m≤46, m is an integer, 27≤n≤68, and n is an integer; or the basematrix includes a row 0 to a row (m−1) and some of a column 0 to acolumn (n−1) in the matrix 30 b-80, where 5≤m≤46, m is an integer,27≤n≤68, and n is an integer.

In one embodiment, for a given base matrix of an LDPC code, shift valuesof non-zero elements in one or more columns in the matrix may beincreased or decreased by an offset Offset_(s). There is little impacton system performance. Compensation values for non-zero elements indifferent columns may be the same or different. For example, one or morecolumns in a matrix are compensated, and offsets for different columnsmay be the same or different. This is not limited in this application.

That there is little impact on system performance means that the impacton the system performance is acceptable and falls within a tolerancerange. For example, the performance deteriorates in an allowable rangein some scenarios or in some ranges. However, the performance isimproved in some scenarios or in some ranges. On the whole, there islittle impact on the performance.

For example, a compensation matrix Hs of the matrix may be obtained byincreasing or decreasing, by an offset Offset_(s), each shift value thatis greater than or equal to 0 and that is in a column s in any one ofthe matrices 30 b-10 to 30 b-80, where Offset_(s) represents an integergreater than or equal to 0, and 0≤s<23. Offset_(s) for one or morecolumns may be the same or different.

A performance diagram shown in FIG. 4 is a decoding performance curveobtained after QPSK modulation and 50 iterations are performed, throughan AWGN channel, on an LDPC code that is encoded based on the matrices30 b-10 to 30 b-80. The horizontal coordinate indicates a length of aninformation bit sequence in a unit of bit, and the vertical coordinateindicates a symbol signal-to-noise ratio (Es/N0) required when acorresponding BLER=0.01, where 120≤K≤8192, code rates are 1/3, 2/5, 1/2,2/3, 3/4, 5/6, and 8/9. The curve is smooth, indicating that the matrixhas good performance in different block lengths.

FIG. 1 to FIG. 3a -1 and FIG. 3a -2, and FIG. 3b -1A to FIG. 3b -8B showstructures of base graphs and base matrices of the LDPC code. To fullydescribe a design of the base graph and/or the base matrix in theembodiments of the present application, Table 2-10 to Table 2-11 belowmay be used for further description.

In a design, the base graph in 10 a in FIG. 1 is a matrix with five rowsand 27 columns, and parameters of the matrix may be represented by Table2-10.

TABLE 2-10 Row index Row weight Columns in (row (row degree/ whichnon-zero elements are located index) row weight) (column position ofnon-zero elements in row) 0 19 0, 1, 2, 3, 5, 6, 9, 10, 11, 12, 13, 15,16, 18, 19, 20, 21, 22, 23 1 19 0, 2, 3, 4, 5, 7, 8, 9, 11, 12, 14, 15,16, 17, 19, 21, 22, 23, 24 2 19 0, 1, 2, 4, 5, 6, 7, 8, 9, 10, 13, 14,15, 17, 18, 19, 20, 24, 25 3 19 0, 1, 3, 4, 6, 7, 8, 10, 11, 12, 13, 14,16, 17, 18, 20, 21, 22, 25 4 3 0, 1, 26

In a design, a size of the base matrix shown in 10 b in FIG. 1 is amatrix with five rows and 27 columns, and parameters of the base matrixmay be represented by Table 2-11.

TABLE 2-11 Row Row weight Columns in which non- Shift values of the non-index (row zero elements are located zero elements (row degree/row(column position of non- (shift values of non- index) weight) zeroelements in row) zeros elements in row) 0 19 0, 1, 2, 3, 5, 6, 9, 10,11, 36, 94, 186, 166, 101, 12, 13, 15, 16, 18, 19, 49, 246, 5, 59, 108,50, 20, 21, 22, 23 79, 106, 167, 25, 73, 127, 0, 0 1 19 0, 2, 3, 4, 5,7, 8, 9, 11, 26, 95, 47, 116, 36, 249, 12, 14, 15, 16, 17, 19, 54, 136,163, 24, 174, 21, 22, 23, 24 66, 85, 183, 198, 61, 1, 0, 0 2 19 0, 1, 2,4, 5, 6, 7, 8, 9, 10, 89, 151, 0, 230, 0, 45, 13, 14, 15, 17, 18, 19,31, 33, 0, 194, 20, 229, 20, 24, 25 0, 91, 42, 0, 232, 0, 0 3 19 0, 1,3, 4, 6, 7, 8, 10, 11, 0, 0, 0, 0, 0, 0, 0, 0, 0, 12, 13, 14, 16, 17,18, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 20, 21, 22, 25 4 3 0, 1, 26 176, 155, 0

In a design, the matrix 30 b-10 in FIG. 3b -1A and FIG. 3b -1B may berepresented by Table 3-10.

TABLE 3-10 Columns in Row Row which non-zero Shift values of the non-index weight elements are located zero elements  0 19  0, 1, 2, 3, 5, 6,9, 10, 36, 94, 186, 166, 101, 49, 11, 12, 13, 15, 16, 18, 246, 5, 59,108, 50, 79, 106, 19, 20, 21, 22, 23 167, 25, 73, 127, 0, 0  1 19  0, 2,3, 4, 5, 7, 8, 9, 11, 26, 95, 47, 116, 36, 249, 54, 12, 14, 15, 16, 17,19, 136, 163, 24, 174, 66, 85, 21, 22, 23, 24 183, 198, 61, 1, 0, 0  219  0, 1, 2, 4, 5, 6, 7, 8, 9, 89, 151, 0, 230, 0, 45, 31, 10, 13, 14,15, 17, 18, 33, 0, 194, 20, 229, 0, 91, 19, 20, 24, 25 42, 0, 232, 0, 0 3 19  0, 1, 3, 4, 6, 7, 8, 10, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 11, 12,13, 14, 16, 17, 0, 0, 0, 0, 0, 0, 0, 0, 0 18, 20, 21, 22, 25  4 3 0, 1,26 176, 155, 0  5 8 0, 1, 3, 12, 16, 21, 226, 134, 243, 17, 92, 22, 27142, 171, 0  6 9 0, 6, 10, 11, 13, 17, 174, 119, 34, 86, 251, 168, 18,20, 28 19, 140, 0  7 7 0, 1, 4, 7, 8, 14, 29 84, 13, 95, 183, 51, 202, 0 8 10  0, 1, 3, 12, 16, 19, 21, 242, 250, 176, 188, 159, 22, 24, 30 180,3, 193, 167, 0  9 9 0, 1, 10, 11, 13, 17, 18, 41, 97, 115, 133, 203, 36,20, 31 198, 122, 0 10 7 1, 2, 4, 7, 8, 14, 32 141, 204, 9, 58, 33, 87, 011 8 0, 1, 12, 16, 21, 22, 111, 126, 163, 125, 188, 23, 33 180, 105, 012 7 0, 1, 10, 11, 13, 18, 34 159, 197, 170, 49, 112, 35, 0 13 6 0, 3,7, 20, 23, 35 121, 84, 173, 2, 205, 0 14 7 0, 12, 15, 16, 17, 21, 55,51, 177, 239, 203, 36 233, 0 15 7 0, 1, 10, 13, 18, 25, 37 56, 133, 77,100, 209, 26, 0 16 6 1, 3, 11, 20, 22, 38 219, 60, 190, 109, 249, 0 17 60, 14, 16, 17, 21, 39 52, 60, 160, 211, 190, 0 18 6 1, 12, 13, 18, 19,40 94, 154, 81, 75, 204, 0 19 6 0, 1, 7, 8, 10, 41 10, 15, 86, 219, 34,0 20 6 0, 3, 9, 11, 22, 42 80, 25, 161, 186, 52, 0 21 6 1, 5, 16, 20,21, 43 208, 110, 40, 124, 53, 0 22 5 0, 12, 13, 17, 44 57, 122, 93, 177,0 23 5 1, 2, 10, 18, 45 26, 101, 100, 129, 0 24 6 0, 3, 4, 11, 22, 4657, 17, 82, 228, 122, 0 25 5 1, 6, 7, 14, 47 61, 148, 114, 80, 0 26 5 0,2, 4, 15, 48 185, 130, 181, 38, 0 27 4 1, 6, 8, 49 183, 101, 194, 0 28 50, 4, 19, 21, 50 77, 31, 149, 19, 0 29 5 1, 14, 18, 25, 51 180, 121,138, 182, 0 30 5 0, 10, 13, 24, 52 62, 170, 37, 220, 0 31 5 1, 7, 22,25, 53 113, 109, 27, 183, 0 32 5 0, 12, 14, 24, 54 224, 83, 33, 112, 033 5 1, 2, 11, 21, 55 83, 169, 241, 47, 0 34 5 0, 7, 15, 17, 56 114,221, 139, 231, 0 35 5 1, 6, 12, 22, 57 171, 195, 81, 204, 0 36 5 0, 14,15, 18, 58 140, 227, 255, 234, 0 37 4 1, 13, 23, 59 101, 115, 51, 0 38 50, 9, 10, 12, 60 215, 214, 29, 80, 0 39 5 1, 3, 7, 19, 61 201, 140, 130,174, 0 40 4 0, 8, 17, 62 87, 81, 77, 0 41 5 1, 3, 9, 18, 63 29, 72, 83,79, 0 42 4 0, 4, 24, 64 7, 27, 98, 0 43 5 1, 16, 18, 25, 65 119, 8, 139,230, 0 44 5 0, 7, 9, 22, 66 249, 30, 162, 113, 0 45 4 1, 6, 10, 67 179,132, 177, 0

In a design, the matrix 30 b-20 in FIG. 3b -2A and FIG. 3b -2B may berepresented by Table 3-20.

TABLE 3-20 Row Columns in which non- Shift values of the non-zero indexRow weight zero elements are located elements 0 19 0, 1, 2, 3, 5, 6, 9,10, 11, 182, 324, 183, 233, 325, 141, 232, 12, 13, 15, 16, 18, 19, 20,258, 71, 196, 242, 226, 224, 10, 21, 22, 23 222, 94, 59, 0, 0 1 19 0, 2,3, 4, 5, 7, 8, 9, 11, 12, 171, 102, 348, 93, 315, 40, 86, 14, 15, 16,17, 19, 21, 22, 260, 81, 327, 229, 128, 269, 236, 23, 24 138, 127, 1, 0,0 2 19 0, 1, 2, 4, 5, 6, 7, 8, 9, 10, 17, 203, 0, 76, 0, 307, 74, 370,0, 13, 14, 15, 17, 18, 19, 20, 47, 21, 90, 0, 238, 51, 0, 253, 0, 0 24,25 3 19 0, 1, 3, 4, 6, 7, 8, 10, 11, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,0, 0, 12, 13, 14, 16, 17, 18, 20, 0, 0, 0, 0, 0 21, 22, 25 4 3 0, 1, 26117, 36, 0 5 8 0, 1, 3, 12, 16, 21, 22, 27 166, 168, 148, 307, 275, 112,191, 0 6 9 0, 6, 10, 11, 13, 17, 18, 20, 123, 345, 235, 40, 217, 131,314, 28 282, 0 7 7 0, 1,4, 7, 8, 14,29 262, 213, 115, 16, 41, 54, 0 8 100, 1, 3, 12, 16, 19, 21, 22, 134, 298, 163, 375, 13, 310, 161, 24,30237, 201, 0 9 9 0, 1, 10, 11, 13, 17, 18, 20, 227, 162, 1, 110, 216,320, 283, 31 262, 0 10 7 1, 2, 4, 7, 8, 14, 32 170, 152, 44, 301, 24,214, 0 11 8 0, 1, 12, 16, 21, 22, 23, 33 73, 37, 328, 70, 127, 305, 345,0 12 7 0, 1, 10, 11, 13, 18, 34 374, 99, 60, 30, 238, 210, 0 13 6 0, 3,7, 20, 23, 35 185, 19, 256, 370, 106, 0 14 7 0, 12, 15, 16, 17, 21, 3645, 15, 55, 73, 222, 311, 0 15 7 0, 1, 10, 13, 18, 25, 37 148, 335, 61,366, 334, 39, 0 16 6 1, 3, 11, 20, 22, 38 138, 85, 167, 69, 110,0 17 60, 14, 16, 17, 21, 39 7, 371, 215, 6, 158, 0 18 6 1, 12, 13, 18, 19,40351, 257, 342, 123, 169, 0 19 6 0, 1, 7, 8, 10,41 269, 13, 116, 43, 135,0 20 6 0, 3, 9, 11, 22, 42 190, 307, 40, 39, 324, 0 21 6 1, 5, 16, 20,21, 43 17, 264, 254, 145, 87, 0 22 5 0, 12, 13, 17,44 273, 325, 77, 189,0 23 5 1, 2, 10, 18, 45 382, 102, 351, 2, 0 24 6 0, 3, 4, 11, 22, 46232, 129, 216, 114, 348, 0 25 5 1, 6, 7, 14, 47 80, 90, 304, 107, 0 26 50, 2, 4, 15, 48 73, 271, 160, 38, 0 27 4 1, 6, 8, 49 209, 68, 32, 0 28 50, 4, 19, 21, 50 40, 236, 165, 225, 0 29 5 1, 14, 18, 25, 51 162, 376,381, 327, 0 30 5 0, 10, 13, 24, 52 34, 351, 51, 43, 0 31 5 1, 7, 22, 25,53 143, 288, 97, 298, 0 32 5 0, 12, 14, 24, 54 288, 257, 318, 62, 0 33 51, 2, 11, 21, 55 251, 179, 383, 337, 0 34 5 0, 7, 15, 17, 56 197, 127,123, 252, 0 35 5 1, 6, 12, 22, 57 259, 345, 4, 232, 0 36 5 0, 14, 15,18, 58 94, 101, 367, 228, 0 37 4 1, 13, 23, 59 1, 70, 242, 0 38 5 0, 9,10, 12, 60 58, 358, 215, 218, 0 39 5 1, 3, 7, 19, 61 262, 11, 241, 42, 040 4 0, 8, 17,62 291, 211, 280, 0 41 5 1, 3, 9, 18,63 56, 321, 370, 115,0 42 4 0, 4, 24, 64 41, 19, 32, 0 43 5 1, 16, 18, 25, 65 125, 133, 193,178, 0 44 5 0, 7, 9, 22, 66 163, 74, 279, 18, 0 45 4 1, 6, 10, 67 46,10, 98, 0

In a design, the matrix 30 b-30 in FIG. 3b -3A and FIG. 3b -3B may berepresented by Table 3-30.

TABLE 3-30 Row Row Columns in which non- Shift values of the non-zeroindex weight zero elements are located elements 0 19 0, 1, 2, 3, 5, 6,9, 10, 11, 190, 13, 82, 205, 251, 214, 5, 12, 13, 15, 16, 18, 19, 217,271, 3, 62, 249, 98, 128, 20, 21, 22, 23 113, 224, 67, 0, 0 1 19 0, 2,3, 4, 5, 7, 8, 9, 11, 119, 12, 250, 216, 66, 114, 12, 14, 15, 16, 17,19, 15, 8, 183, 189, 184, 157, 21, 22, 23, 24 185, 188, 7, 106, 1, 0, 02 19 0, 1, 2, 4, 5, 6, 7, 8, 9, 204, 303, 0, 297, 0, 113, 196, 10, 13,14, 15, 17, 18, 225, 0, 42, 18, 51, 0, 134, 19, 20, 24, 25 152, 0, 166,0, 0 3 19 0, 1, 3, 4, 6, 7, 8, 10, 11, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,12, 13, 14, 16, 17, 18, 0, 0, 0, 0, 0, 0, 0, 0 20, 21, 22, 25 4 3 0, 1,26 60, 32, 0 5 8 0, 1, 3, 12, 16, 21, 22, 27 86, 220, 210, 172, 271,218, 79, 0 6 9 0, 6, 10, 11, 13, 17, 18, 108, 247, 281, 13, 258, 146,20, 28 23, 255, 0 7 7 0, 1, 4, 7, 8, 14, 29 258, 308, 59, 283, 101, 95,0 8 10 0, 1, 3, 12, 16, 19, 21, 63, 181, 236, 199, 190, 180, 22, 24, 30288, 257, 135, 0 9 9 0, 1, 10, 11, 13, 17, 18, 266, 74, 9, 239, 273, 10,117, 20, 31 118, 0 10 7 1, 2, 4, 7, 8, 14, 32 157, 210, 173, 301, 87,299, 0 11 8 0, 1, 12, 16, 21, 22, 23, 111, 118, 174, 21, 293, 290, 33294, 0 12 7 0, 1, 10, 11, 13, 18, 34 89, 242, 194, 196, 13, 183, 0 13 60, 3, 7, 20, 23, 35 78, 248, 171, 286, 176, 0 14 7 0, 12, 15, 16, 17,21, 36 86, 275, 156, 119, 31, 267, 0 15 7 0, 1, 10, 13, 18, 25, 37 146,48, 195, 84, 56, 294, 0 16 6 1, 3, 11, 20, 22, 38 214, 43, 215, 193,259, 0 17 6 0, 14, 16, 17, 21, 39 153, 317, 172, 270, 307, 0 18 6 1, 12,13, 18, 19, 40 294, 47, 264, 300, 202, 0 19 6 0, 1, 7, 8, 10,41 61, 237,42, 252, 151, 0 20 6 0, 3, 9, 11, 22, 42 73, 114, 315, 149, 0, 0 21 6 1,5, 16, 20, 21, 43 298, 122, 168, 216, 81, 0 22 5 0, 12, 13, 17, 44 282,296, 127, 114, 0 23 5 1, 2, 10, 18, 45 128, 130, 169, 124, 0 24 6 0, 3,4, 11, 22, 46 105, 77, 107, 211, 276, 0 25 5 1, 6, 7, 14, 47 107, 150,58, 103, 0 26 5 0, 2, 4, 15, 48 254, 243, 10, 156, 0 27 4 1, 6, 8, 49298, 62, 299, 0 28 5 0, 4, 19, 21, 50 168, 253, 12, 39, 0 29 5 1, 14,18, 25, 51 250, 307, 89, 125, 0 30 5 0, 10, 13, 24, 52 264, 166, 247, 8,0 31 5 1, 7, 22, 25, 53 173, 7, 1, 178, 0 32 5 0, 12, 14, 24, 54 288,227, 209, 219, 0 33 5 1, 2, 11, 21, 55 313, 100, 228, 132, 0 34 5 0, 7,15, 17, 56 3, 100, 156, 205, 0 35 5 1, 6, 12, 22, 57 207, 89, 91, 144, 036 5 0, 14, 15, 18, 58 255, 66, 158, 11, 0 37 4 1, 13, 23, 59 281, 184,203, 0 38 5 0, 9, 10, 12, 60 180, 125, 136, 111, 0 39 5 1, 3, 7, 19, 61233, 141, 309, 246, 0 40 4 0, 8, 17, 62 44, 199, 57, 0 41 5 1, 3, 9, 18,63 191, 225, 159, 84, 0 42 4 0, 4, 24, 64 180, 98, 226, 0 43 5 1, 16,18, 25, 65 318, 80, 29, 219, 0 44 5 0, 7, 9, 22, 66 253, 304, 266, 36, 045 4 1, 6, 10, 67 105, 10, 142, 0

In a design, the matrix 30 b-40 in FIG. 3b -4A and FIG. 3b -4B may berepresented by Table 3-40.

TABLE 3-40 Columns in which Row Row non-zero Shift values of thenon-zero index weight elements are located elements 0 19 0, 1, 2, 3, 5,6, 9, 189, 174, 162, 53, 32, 120, 143, 10, 11, 12, 13, 15, 79, 7, 47,188, 72, 5, 40, 141, 69, 16, 18, 19, 20, 67, 0, 0 21, 22, 23 1 19 0, 2,3, 4, 5, 7, 8, 9, 36, 195, 130, 45, 133, 147, 98, 11, 12, 14, 15, 16,25, 205, 166, 60, 67, 52, 190, 17, 19, 21, 22, 127, 31, 1, 0, 0 23, 24 219 0, 1, 2, 4, 5, 6, 7, 8, 118, 25, 0, 32, 0, 19, 55, 191, 0, 9, 10, 13,14, 15, 125, 2, 68, 0, 66, 44, 0, 179, 0, 0 17, 18, 19, 20, 24, 25 3 190, 1, 3, 4, 6, 7, 8, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 10, 11, 12,13, 14, 0, 0, 0, 0, 0, 0 16, 17, 18, 20, 21, 22, 25 4 3 0, 1, 26 71, 46,0 5 8 0, 1, 3, 12, 16, 21, 195, 182, 172, 37, 218, 118, 150, 22, 27 0 69 0, 6, 10, 11, 13, 17, 81, 146, 121, 44, 170, 201, 185, 18, 20, 28 3, 07 7 0, 1, 4, 7, 8, 14, 29 85, 181, 144, 118, 12, 43, 0 8 10 0, 1, 3, 12,16, 19, 213, 91, 3, 28, 136, 5, 98, 148, 21, 22, 24, 30 100, 0 9 9 0, 1,10, 11, 13, 17, 208, 125, 112, 27, 190, 175, 130, 18, 20, 31 121, 0 10 71, 2, 4, 7, 8, 14, 32 128, 142, 80, 35, 214, 22, 0 11 8 0, 1, 12, 16,21, 22, 20, 153, 220, 29, 135, 159, 64, 0 23, 33 12 7 0, 1, 10, 11, 13,18, 194, 155, 103, 2, 205, 39, 0 34 13 6 0, 3, 7, 20, 23, 35 81, 52, 15,219, 98, 0 14 7 0, 12, 15, 16, 17, 153, 64, 167, 126, 63, 24, 0 21, 3615 7 0, 1, 10, 13, 18, 25, 133, 125, 134, 30, 10, 25, 0 37 16 6 1, 3,11, 20, 22, 38 81, 169, 30, 42, 46, 0 17 6 0, 14, 16, 17, 21, 39 164,89, 26, 126, 106, 0 18 6 1, 12, 13, 18, 19,40 56, 156, 155, 124, 174, 019 6 0, 1, 7, 8, 10, 41 196, 9, 209, 193, 116, 0 20 6 0, 3, 9, 11, 22,42 62, 80, 162, 92, 37, 0 21 6 1, 5, 16, 20, 21, 43 215, 148, 142, 21,22, 0 22 5 0, 12, 13, 17, 44 153, 40, 20, 128, 0 23 5 1,2, 10, 18, 4535, 167, 64, 216, 0 24 6 0, 3, 4, 11, 22, 46 153, 138, 10, 67, 219, 0 255 1, 6, 7, 14, 47 147, 195, 89, 166, 0 26 5 0, 2, 4, 15, 48 219, 38, 97,182, 0 27 4 1, 6, 8, 49 72, 152, 17, 0 28 5 0, 4, 19, 21, 50 0, 150,221, 86, 0 29 5 1, 14, 18, 25, 51 61, 154, 119, 76,0 30 5 0, 10, 13, 24,52 92, 30, 137, 42, 0 31 5 1, 7, 22, 25, 53 9, 25, 48, 111, 0 32 5 0,12, 14, 24, 54 112, 64, 31, 15, 0 33 5 1, 2, 11, 21, 55 134, 91, 108,149, 0 34 5 0, 7, 15, 17, 56 198, 201, 95, 153, 0 35 5 1, 6, 12, 22, 57138, 30, 45, 192, 0 36 5 0, 14, 15, 18, 58 70, 193, 57, 204, 0 37 4 1,13, 23, 59 81, 89, 26, 0 38 5 0, 9, 10, 12, 60 111, 85, 215, 145, 0 39 51, 3, 7, 19, 61 166, 135, 189, 213, 0 40 4 0, 8, 17, 62 112, 184, 17, 041 5 1, 3, 9, 18, 63 26, 35, 176, 62, 0 42 4 0, 4, 24, 64 134, 13, 146,0 43 5 1, 16, 18, 25, 65 186, 116, 113, 166, 0 44 5 0, 7, 9, 22, 66 23,33, 86, 192, 0 45 4 1, 6, 10, 67 7, 172, 186, 0

In a design, the matrix 30 b-50 in FIG. 3b -5A and FIG. 3b -5B may berepresented by Table 3-50.

TABLE 3-50 Row Columns in which non- Shift values of the non-zero indexRow weight zero elements are located elements 0 19 0, 1, 2, 3, 5, 6, 9,10, 11, 76, 207, 77, 49, 158, 285, 173, 12, 13, 15, 16, 18, 19, 20, 219,125, 78, 34, 142, 272, 62, 21, 22, 23 204, 223, 176, 0, 0 1 19 0, 2, 3,4, 5, 7, 8, 9, 11, 12, 96, 237, 27, 65, 243, 97, 246, 2, 14, 15, 16, 17,19, 21, 22, 22, 226, 257, 141, 215, 231, 35, 23, 24 254, 1, 0, 0 2 19 0,1, 2, 4, 5, 6, 7, 8, 9, 10, 59, 68, 0, 109, 0, 57, 189, 269, 0, 13, 14,15, 17, 18, 19, 20, 92, 132, 69, 0, 170, 227, 0, 70, 0, 24, 25 0 3 19 0,1, 3, 4, 6, 7, 8, 10, 11, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 12, 13,14, 16, 17, 18, 20, 0, 0, 0, 0, 0, 0 21, 22, 25 4 3 0, 1, 26 5, 128, 0 58 0, 1, 3, 12, 16, 21, 22, 27 1, 108, 93, 64, 45, 31, 200, 0 6 9 0, 6,10, 11, 13, 17, 18, 20, 191, 136, 146, 242, 40, 125, 95, 28 253, 0 7 70, 1, 4, 7, 8, 14, 29 87, 253, 261, 2, 157, 274, 0 8 10 0, 1, 3, 12, 16,19, 21, 22, 236, 139, 36, 21, 156, 131, 287, 24, 30 235, 169, 0 9 9 0,1, 10, 11, 13, 17, 18, 20, 121, 230, 186, 159, 70, 61, 257, 31 173, 0 107 1, 2, 4, 7, 8, 14, 32 216, 45, 212, 260, 82, 166, 0 11 8 0, 1, 12, 16,21, 22, 23, 33 42, 14, 35, 99, 15, 39, 287, 0 12 7 0, 1, 10, 11, 13, 18,34 231, 225, 236, 149, 50, 179, 0 13 6 0, 3, 7, 20, 23, 35 265, 86, 277,182, 138, 0 14 7 0, 12, 15, 16, 17, 21, 36 220, 259, 218, 198, 281, 117,0 15 7 0, 1, 10, 13, 18, 25, 37 124, 188, 143, 146, 11, 6, 0 16 6 1,3,11, 20, 22, 38 195, 59, 208, 261, 230, 0 17 6 0, 14, 16, 17, 21, 39 134,274, 35, 108, 122, 0 18 6 1, 12, 13, 18, 19,40 273, 154, 96, 269, 83, 019 6 0, 1, 7, 8, 10, 41 234, 60, 107, 105, 121, 0 20 6 0, 3, 9, 11, 22,42 194, 57, 241, 60, 196, 0 21 6 1,5, 16, 20, 21, 43 70, 114, 108, 11,208, 0 22 5 0, 12, 13, 17, 44 70, 172, 193, 45, 0 23 5 1, 2, 10, 18, 45146, 84, 258, 97, 0 24 6 0, 3, 4, 11, 22, 46 201, 216, 212, 136, 78, 025 5 1, 6, 7, 14, 47 38, 50, 188, 267, 0 26 5 0, 2, 4, 15, 48 45, 113,0, 242, 0 27 4 1, 6, 8, 49 213, 269, 172, 0 28 5 0, 4, 19, 21, 50 66,160, 1, 266, 0 29 5 1, 14, 18, 25, 51 265, 39, 185, 86, 0 30 5 0, 10,13, 24, 52 118, 186, 161, 34, 0 31 5 1, 7, 22, 25, 53 151, 140, 33, 18,0 32 5 0, 12, 14, 24, 54 231, 201, 98, 269, 0 33 5 1,2, 11,21, 55 205,259, 274, 129,0 34 5 0,7, 15, 17, 56 277, 231, 229, 164, 0 35 5 1, 6,12, 22, 57 134, 7, 204, 27, 0 36 5 0, 14, 15, 18, 58 181, 168, 149, 12,0 37 4 1, 13, 23, 59 280, 132, 101, 0 38 5 0, 9, 10, 12, 60 61, 227,207, 56, 0 39 5 1, 3, 7, 19, 61 283, 172, 286, 228, 0 40 4 0, 8, 17, 6211, 97, 243, 0 41 5 1, 3, 9, 18, 63 274, 216, 111, 65, 0 42 4 0, 4, 24,64 156, 177, 171, 0 43 5 1, 16, 18, 25, 65 77, 282, 183, 110, 0 44 5 0,7, 9, 22, 66 118, 169, 210, 69, 0 45 4 1, 6, 10, 67 178, 37, 15, 0

In a design, the matrix 30 b-60 in FIG. 3b -6A and FIG. 3b -6B may berepresented by Table 3-60.

TABLE 3-60 Row Columns in which Shift values of the non-zero index Rowweight non-zero elements are located elements 0 19 0, 1, 2, 3, 5, 6, 9,10, 11, 26, 118, 197, 59, 339, 9, 306, 12, 13, 15, 16, 18, 19, 20, 280,219, 149, 227, 321, 298, 62, 21, 22, 23 260, 55, 10, 0, 0 1 19 0,2, 3,4,5, 7, 8, 9, 11, 12, 292, 33, 174, 25, 78, 21, 39, 50, 14, 15, 16, 17,19, 21, 22, 80, 233, 203, 90, 305, 316, 164, 23, 24 70, 1, 0, 0 2 19 0,1, 2, 4, 5, 6, 7, 8, 9, 10, 315, 270, 0, 194, 0, 261, 347, 53, 13, 14,15, 17, 18, 19, 20, 0, 32, 68, 224, 0, 267, 191, 0, 24, 25 192, 0, 0 319 0, 1, 3, 4, 6, 7, 8, 10, 11, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,12, 13, 14, 16, 17, 18, 20, 0, 0, 0, 0, 0, 0 21, 22, 25 4 3 0, 1, 26 14,30, 0 5 8 0, 1, 3, 12, 16, 21, 22, 27 197, 77, 129, 265, 230, 92, 207, 06 9 0, 6, 10, 11, 13, 17, 18, 20, 175, 192, 62, 156, 247, 161, 296, 28110, 0 7 7 0, 1, 4, 7, 8, 14, 29 27, 130, 119, 18, 334, 147, 0 8 10 0,1, 3, 12, 16, 19, 21, 22, 102, 215, 126, 314, 305, 74, 238, 24, 30 115,189, 0 9 9 0, 1, 10, 11, 13, 17, 18, 20, 157, 232, 313, 136, 175, 304,31 251, 14, 0 10 7 1, 2, 4, 7, 8, 14, 32 282, 148, 138, 344, 95, 27, 011 8 0, 1, 12, 16, 21, 22, 23, 33 158, 28, 7, 267, 253, 295, 311,0 12 70, 1, 10, 11, 13, 18, 34 350, 48, 351, 185, 278, 176, 0 13 6 0, 3, 7,20, 23, 35 334, 30, 346, 168, 104, 0 14 7 0, 12, 15, 16, 17, 21, 36 164,333, 57, 116, 117, 130, 0 15 7 0, 1, 10, 13, 18, 25, 37 312, 320, 217,222, 201, 33, 0 16 6 1, 3, 11, 20, 22, 38 54, 67, 219, 332, 170, 0 17 60, 14, 16, 17, 21, 39 161, 331, 339, 194, 230, 0 18 6 1, 12, 13, 18, 19,40 33, 123, 207, 172, 173, 0 19 6 0, 1, 7, 8, 10, 41 221, 62, 74, 37,29, 0 20 6 0, 3, 9, 11, 22, 42 145, 139, 24, 0, 6, 0 21 6 1, 5, 16, 20,21, 43 115, 258, 248, 215, 239, 0 22 5 0, 12, 13, 17, 44 242, 230, 165,175, 0 23 5 1, 2, 10, 18, 45 63, 94, 241, 52, 0 24 6 0, 3, 4, 11, 22, 46249, 142, 214, 58, 160, 0 25 5 1, 6, 7, 14, 47 244, 78, 53, 285, 0 26 50, 2, 4, 15, 48 34, 140, 178, 36, 0 27 4 1, 6, 8, 49 256, 50, 230, 0 285 0, 4, 19, 21, 50 107, 224, 147, 241, 0 29 5 1, 14, 18, 25, 51 277,287, 194, 297, 0 30 5 0, 10, 13, 24, 52 22, 284, 134, 41, 0 31 5 1, 7,22, 25, 53 343, 320, 48, 270, 0 32 5 0, 12, 14, 24, 54 337, 122, 245,46, 0 33 5 1,2, 11, 21, 55 297, 157, 218, 43, 0 34 5 0, 7, 15, 17, 56316, 11, 131, 135, 0 35 5 1, 6, 12, 22, 57 114, 319, 163, 328, 0 36 5 0,14, 15, 18, 58 214, 88, 345, 142, 0 37 4 1, 13, 23, 59 277, 50, 220, 038 5 0, 9, 10, 12, 60 167, 312, 53, 43, 0 39 5 1, 3, 7, 19,61 190, 311,63, 36, 0 40 4 0, 8, 17, 62 320, 189, 282, 0 41 5 1, 3, 9, 18, 63 127,260, 344, 296, 0 42 4 0, 4, 24, 64 10, 148, 34, 0 43 5 1, 16, 18, 25, 65112, 216, 104, 162, 0 44 5 0, 7, 9, 22, 66 91, 22, 257, 165, 0 45 4 1,6, 10, 67 164, 14, 295, 0

In a design, the matrix 30 b-70 in FIG. 3b -7A and FIG. 3b -7B may berepresented by Table 3-70.

TABLE 3-70 Row Columns in which Shift values of the non-zero index Rowweight non-zero elements are located elements 0 19 0, 1, 2, 3, 5, 6, 9,10, 11, 101, 37, 142, 86, 154, 107, 77, 19, 12, 13, 15, 16, 18, 19, 20,189, 114, 134, 167, 100, 200, 140, 21, 22, 23 191, 106, 0, 0 1 19 0, 2,3, 4, 5, 7, 8, 9, 11, 12, 149, 111, 142, 92, 93, 155, 6, 44, 14, 15, 16,17, 19, 21, 22, 98, 125, 17, 86, 146, 195, 184, 23, 24 135, 1, 0, 0 2 190, 1, 2, 4, 5, 6, 7, 8, 9, 10, 189, 179, 0, 79, 0, 8, 3, 61, 0, 28, 13,14, 15, 17, 18, 19, 20, 192, 89, 0, 82, 67, 0, 120, 0, 0 24, 25 3 19 0,1, 3, 4, 6, 7, 8, 10, 11, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 12,13, 14, 16, 17, 18, 20, 0, 0, 0, 0, 0 21, 22, 25 4 3 0, 1, 26 67, 40, 05 8 0, 1, 3, 12, 16, 21, 22, 27 119, 168, 75, 20, 186, 35, 162, 0 6 9 0,6, 10, 11, 13, 17, 18, 20, 92, 183, 110, 153, 122, 102, 51, 28 177, 0 77 0, 1, 4, 7, 8, 14, 29 107, 70, 144, 175, 62, 165, 0 8 10 0, 1, 3, 12,16, 19, 21, 22, 157, 160, 159, 197, 44, 141, 175, 24, 30 34, 179, 0 9 90, 1, 10, 11, 13, 17, 18, 20, 66, 207, 8, 160, 13, 125, 135, 61, 31 0 107 1, 2, 4, 7, 8, 14, 32 21, 62, 161, 145, 181, 195, 0 11 8 0, 1, 12, 16,21, 22, 23, 33 156, 46, 94, 48, 36, 122, 176, 0 12 7 0, 1, 10, 11, 13,18, 34 189, 165, 91, 15, 1, 29, 0 13 6 0, 3, 7, 20, 23, 35 38, 157, 169,181, 4, 0 14 7 0, 12, 15, 16, 17, 21, 36 73, 43, 194, 167, 32, 204, 0 157 0, 1, 10, 13, 18, 25, 37 39, 0, 178, 57, 11, 172, 0 16 6 1, 3, 11, 20,22, 38 38, 65, 115, 164, 125, 0 17 6 0, 14, 16, 17, 21, 39 62, 207, 98,31, 120, 0 18 6 1, 12, 13, 18, 19,40 170, 124, 25, 172, 70, 0 19 6 0, 1,7, 8, 10,41 93, 181, 117, 110, 53, 0 20 6 0, 3, 9, 11, 22, 42 65, 144,203, 37, 142, 0 21 6 1, 5, 16, 20, 21, 43 84, 156, 197, 152, 71, 0 22 50, 12, 13, 17, 44 3, 180, 5, 148, 0 23 5 1,2, 10, 18,45 120, 170, 4,130, 0 24 6 0, 3,4, 11, 22, 46 180, 57, 133, 182, 165, 0 25 5 1, 6, 7,14, 47 150, 190, 24, 143, 0 26 5 0, 2, 4, 15, 48 177, 86, 75, 200, 0 274 1, 6, 8, 49 184, 90, 111, 0 28 5 0, 4, 19, 21, 50 49, 10, 12, 37, 0 295 1, 14, 18, 25, 51 30, 117, 44, 157, 0 30 5 0, 10, 13, 24, 52 140, 65,89, 8, 0 31 5 1, 7, 22, 25, 53 68, 169, 190, 24, 0 32 5 0, 12, 14, 24,54 60, 127, 50, 55, 0 33 5 1,2, 11, 21, 55 187, 146, 78, 197,0 34 5 0,7, 15, 17, 56 125, 184, 190, 85, 0 35 5 1, 6, 12, 22, 57 38, 129, 65,76, 0 36 5 0, 14, 15, 18, 58 62, 183, 202, 206, 0 37 4 1, 13, 23, 59154, 44, 59, 0 38 5 0, 9, 10, 12, 60 170, 175, 108, 0, 0 39 5 1, 3, 7,19,61 20, 127, 38, 110, 0 40 4 0, 8, 17, 62 177, 41, 113, 0 41 5 1, 3,9, 18, 63 188, 48, 205, 140, 0 42 4 0, 4, 24, 64 193, 182, 86, 0 43 5 1,16, 18, 25, 65 142, 155, 140, 59, 0 44 5 0, 7, 9, 22, 66 172, 56, 138,182, 0 45 4 1, 6, 10, 67 21, 12, 183, 0

In a design, the matrix 30 b-80 in FIG. 3b -8A and FIG. 3b -8B may berepresented by Table 3-80.

TABLE 3-80 Row Columns in which Shift values of the non-zero index Rowweight non-zero elements are located elements 0 19 0, 1,2, 3, 5, 6,9,10, 11, 189, 204, 133, 17, 181, 18, 7, 6, 12, 13, 15, 16, 18, 19, 20,237, 171, 65, 224, 8, 55, 93, 110, 21, 22, 23 212, 0, 0 1 19 0, 2, 3, 4,5, 7, 8, 9, 11, 12, 113, 82, 29, 131, 83, 223, 34, 62, 14, 15, 16, 17,19, 21, 22, 130, 26, 33, 72, 135, 136, 156, 23, 24 208, 1, 0, 0 2 19 0,1, 2, 4, 5, 6, 7, 8, 9, 10, 95, 175, 0, 134, 0, 2, 19, 129, 0, 13, 14,15, 17, 18, 19, 20, 171, 174, 42, 0, 98, 6, 0, 22, 0, 0 24, 25 3 19 0,1, 3, 4, 6, 7, 8, 10, 11, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 12, 13,14, 16, 17, 18, 20, 0, 0, 0, 0, 0, 0 21, 22, 25 4 3 0, 1, 26 83, 51, 0 58 0, 1, 3, 12, 16, 21, 22, 27 89, 210, 134, 51, 151, 67, 223, 0 6 9 0,6, 10, 11, 13, 17, 18, 20, 199, 158, 37, 192, 184, 231, 47, 28 31, 0 7 70, 1, 4, 7, 8, 14, 29 152, 110, 79, 91, 195, 100, 0 8 10 0, 1, 3, 12,16, 19, 21, 22, 4, 78, 104, 77, 165, 176, 6, 100, 24, 30 79, 0 9 9 0, 1,10, 11, 13, 17, 18, 20, 148, 155, 36, 99, 42, 71, 128, 86, 31 0 10 7 1,2, 4, 7, 8, 14, 32 134, 146, 117, 96, 76, 162, 0 11 8 0, 1, 12, 16, 21,22, 23, 33 187, 75, 22, 133, 147, 39, 195, 0 12 7 0, 1, 10, 11, 13, 18,34 182, 234, 104, 112, 94, 69, 0 13 6 0, 3, 7, 20, 23, 35 53, 5, 206,216, 147, 0 14 7 0, 12, 15, 16, 17, 21, 36 213, 21, 105, 86, 228, 102, 015 7 0, 1, 10, 13, 18, 25, 37 213, 166, 223, 127, 179, 56, 0 16 6 1, 3,11, 20, 22, 38 47, 102, 184, 239, 20, 0 17 6 0, 14, 16, 17, 21, 39 98,112, 78, 107, 93, 0 18 6 1, 12, 13, 18, 19,40 54, 14, 29, 126, 148, 0 196 0, 1, 7, 8, 10,41 53, 115, 153, 165, 210, 0 20 6 0, 3, 9, 11, 22, 42225, 93, 65, 102, 100, 0 21 6 1, 5, 16, 20, 21, 43 220, 204, 178, 159,37, 0 22 5 0, 12, 13, 17, 44 18, 234, 120, 113, 0 23 5 1,2, 10, 18, 45160, 181, 29, 180, 0 24 6 0, 3, 4, 11, 22, 46 6, 94, 176, 238, 182, 0 255 1, 6, 7, 14, 47 66, 44, 207, 90, 0 26 5 0, 2, 4, 15, 48 86, 233, 30,80, 0 27 4 1, 6, 8, 49 212, 209, 28, 0 28 5 0, 4, 19, 21, 50 87, 19, 53,13, 0 29 5 1, 14, 18, 25, 51 185, 135, 143, 98, 0 30 5 0, 10, 13, 24, 52151, 87, 232, 152, 0 31 5 1, 7, 22, 25, 53 95, 229, 17, 113, 0 32 5 0,12, 14, 24, 54 111, 224, 115, 212, 0 33 5 1, 2, 11, 21, 55 182, 61, 204,172, 0 34 5 0, 7, 15, 17, 56 230, 137, 19, 234, 0 35 5 1, 6, 12, 22, 5737, 125, 112, 126, 0 36 5 0, 14, 15, 18, 58 109, 72, 239, 39, 0 37 4 1,13, 23, 59 154, 132, 119, 0 38 5 0, 9, 10, 12, 60 112, 158, 194, 203, 039 5 1, 3, 7, 19, 61 224, 140, 0, 68, 0 40 4 0, 8, 17, 62 8, 179, 78, 041 5 1, 3, 9, 18, 63 120, 71, 171, 178, 0 42 4 0, 4, 24, 64 39, 10, 192,0 43 5 1, 16, 18, 25, 65 169, 211, 209, 184, 0 44 5 0, 7, 9, 22, 66 227,12, 68, 74, 0 45 4 1, 6, 10, 67 91, 0, 204, 0

It may be understood that, FIG. 1 to FIG. 3a -1 and FIG. 3a -2, FIG. 3b-1A to FIG. 3b -8B, and Table 2-10, Table 2-11, and Table 3-10 to Table3-80 are intended to help understand designs of the base graph and thematrix, and representation forms of the designs are not limited torepresentation forms of FIG. 1 to FIG. 3a -1 and FIG. 3a -2 and FIG. 3b-1A to FIG. 3b -8B, or Table 2-10, Table 2-11, and Table 3-10 to Table3-80. Another possible variation may further be included.

In one embodiment, the parameter “row weight” in Table 2-10, Table 2-11,and Table 3-10 to Table 3-80 may alternatively be omitted. A quantity ofnon-zero elements in a row may be learned from columns in which thenon-zero elements in the row are located, and therefore, a row weight islearned.

In one embodiment, parameter values in “columns in which non-zeroelements are located” in Table 2-10, Table 2-11, and Table 3-10 to Table3-80 may not be arranged in ascending order, provided that the parametervalues are indexed to the columns in which the non-zero elements arelocated. In addition, parameter values in “shift values of the non-zeroelements” in Table 2-10, Table 2-11, and Table 3-10 to Table 3-80 arenot necessarily arranged in a column sequence either, provided that theparameter values in “shift values of the non-zero elements” are in aone-to-one correspondence with the parameter values in “columns in whichnon-zero elements are located”.

FIG. 5 shows a design of a data processing process. The data processingprocess may be implemented by a communications apparatus. Thecommunications apparatus may be a base station, a terminal, anotherentity, or the like, for example, a communications chip or anencoder/decoder.

Part 501: Obtain an input sequence.

In one embodiment, a to-be-encoded input sequence may be an informationbit sequence. The information bit sequence is also referred to as a codeblock (code block) sometimes, for example, may be an output sequenceobtained after performing code block division on a transport block. Inone embodiment, a to-be-decoded input sequence may be a soft valuesequence of an LDPC code.

Part 502: Encode/decode the input sequence based on an LDPC matrix,where a base matrix of the LDPC matrix may be any base matrix in theforegoing examples.

In one embodiment, the LDPC matrix may be obtained based on a liftingfactor Z and the base matrix.

In one embodiment, related parameters of the LDPC matrix may be saved,and these parameters include one or more of the following:

(a) parameters used to obtain any base matrix listed in the foregoingembodiments. The base matrix may be obtained based on the parameters.For example, the parameters may include one or more of the following: arow index, a row weight, a position of a non-zero element, a shift valuein the base matrix, a shift value of the non-zero element and acorresponding position, an offset, a lifting factor, a base graph, acode rate, and the like.

(b) any base matrix listed in the foregoing embodiments;

(c) a compensation matrix Hs obtained by compensating at least onecolumn in any base matrix listed in the foregoing embodiments;

(d) a matrix obtained by lifting a base matrix or a compensation matrixHs of the base matrix;

(e) a base matrix obtained by performing a row/column transform on anybase matrix listed in the foregoing embodiments or the compensationmatrix Hs.

(f) a matrix obtained by lifting the base matrix or the compensationmatrix Hs obtained through the row/column transform;

(g) a base matrix obtained by shortening or puncturing any base matrixlisted in the foregoing embodiments or the compensation matrix Hs.

In one embodiment, the encoding/decoding the input sequence based on thelow density parity check LDPC matrix may be performed in one or more ofthe following manners in an encoding/decoding process:

i. obtaining a base matrix based on (a), and encoding/decoding based onthe obtained base matrix; or performing row/column switching based onthe obtained base matrix, and encoding/decoding based on arow/column-transformed base matrix; or encoding/decoding based on acompensation matrix of the obtained base matrix; or encoding/decodingbased on a matrix obtained by performing a row/column transform on acompensation matrix Hs of the obtained base matrix. In one embodiment,the encoding/decoding based on the base matrix or the compensationmatrix Hs herein may alternatively include encoding/decoding based on alifting matrix of the base matrix or a lifting matrix of thecompensation matrix Hs, or encoding/decoding based on a matrix obtainedby shortening or puncturing the base matrix or the compensation matrix;

ii. encoding/decoding based on the base matrix (the saved base matrix Hor Hs, or a saved base matrix obtained by performing the row/columntransform on the base matrix H or Hs) saved in (b), (c), (d), or (e), orperforming a row/column transform on the saved base matrix, andencoding/decoding based on a row/column transformed base matrix. In oneembodiment, the encoding/decoding based on the base matrix or thecompensation matrix Hs herein may alternatively includeencoding/decoding based on a lifting matrix of the base matrix or alifting matrix of the compensation matrix Hs, or encoding/decoding basedon a matrix obtained by shortening or puncturing the base matrix or thecompensation matrix; and

iii. encoding/decoding based on (d), (f) or (g).

Part 503: Output an encoded/decoded bit sequence.

FIG. 6 shows a design of a processed data obtaining process, and thedesign may be applied to part 502 in FIG. 5.

Part 601: Obtain a lifting factor Z.

In one embodiment, the lifting factor Z may be determined based on alength K of an input sequence. For example, in a supported liftingfactor set, a minimum Z₀ may be found and used as a value of the liftingfactor Z, and Kb·Z₀≥2 K. In one embodiment, Kb may represent a quantityof information bit columns in a base matrix of an LDPC code. In a basegraph 30 a, a quantity Kb_(max) of information bit columns is equal to22. It is assumed that a lifting factor set supported by the base graph30 a is {24, 26, 28, 30, 32, 36, 40, 44, 48, 52, 56, 60, 64, 72, 80, 88,96, 104, 112, 120, 128, 144, 160, 176, 192, 208, 224, 240, 256, 288,320, 352, 384}.

If the length K of the input sequence is 529 bits, Z is 26. If thelength K of the input sequence is 5000 bits, Z is 240. It should benoted that, this is merely an example, and the present application isnot limited thereto.

For another example, a value of Kb may also vary with a value of K, anddoes not exceed the quantity of information bit columns in the basematrix of the LDPC code. For example, when K is greater than a firstthreshold, Kb=22; or when K is less than or equal to a first threshold,Kb=21. Alternatively, when K is greater than a first threshold, Kb=22;when K is less than or equal to a first threshold, and K is greater thana second threshold, Kb=21; or when K is less than or equal to a secondthreshold, Kb=20. It should be noted that, this is merely an example fordescription, and the present application is not limited thereto.

In addition, based on any one of the foregoing embodiments, for aparticular information length K, for example, when 104≤K≤512, Z mayalternatively be selected according to a rule defined in a system. Foranother length, K is still selected according to any one of theforegoing embodiments, for example, the minimum Z₀ is selected, whereKb·Z₀≥K is met. The value of Kb is 22 or is determined based on athreshold.

In a design, when 104≤K≤512, Z is selected as shown in Table 4-1, andanother length is selected according to any one of the foregoingembodiments.

TABLE 4-1 Value range of K Lifting factor Z 104 to 119 6 120 to 127 8128 to 135 6 136 to 183 8 184 to 199 10 200 to 271 12 272 to 279 16 280to 287 13 288 to 303 16 304 to 311 18 312 to 327 16 328 to 335 20 336 to375 18 376 to 383 20 384 to 399 18 400 to 415 20 416 to 431 22 432 to447 20 448 to 463 22 464 to 479 24 480 to 487 28 488 to 503 26 504 to511 24

The lifting factor Z may be determined by a communications apparatusbased on the length K of the input sequence, or may be obtained by acommunications apparatus from another entity (for example, a processor).

Part 602: Obtain an LDPC matrix based on the lifting factor and a basematrix.

The base matrix is any base matrix listed in the foregoing embodiments,or a compensation matrix obtained by compensating at least one column inany base matrix listed above, or a base matrix in which a row sequenceis changed, a column sequence is changed, or both a row sequence and acolumn sequence are changed compared with any base matrix listed aboveor a compensation matrix. The base graph of the base matrix includes atleast a submatrix A and a submatrix B. In one embodiment, a submatrix C,a submatrix D, and a submatrix E may further be included. For eachsubmatrix, refer to the descriptions in the foregoing embodiments.Details are not described herein.

In one embodiment, a corresponding base matrix is determined based onthe lifting factor Z, and the base matrix is permuted based on thelifting factor Z to obtain the LDPC matrix.

In one embodiment, a correspondence between a lifting factor and a basematrix may be stored, and a corresponding base matrix is determinedbased on the lifting factor Z obtained in part 601.

For example, Z is 26, and a=13. The base matrix may include a row 0 to arow 4 and a column 0 to a column 26 in the matrix 30 b-7, or the basematrix includes a row 0 to a row 4 and some of a column 0 to a column 26in the matrix 30 b-7. Further, the base matrix further includes the row0 to a row (m−1) and the column 0 to a column (n−1) in the matrix, where5≤m≤46, m is an integer, 27≤n≤68, n is an integer; or the base matrixincludes the row 0 to a row (m−1) and the column 0 to a column (n−1) inthe matrix 30 b-7, where 5≤m≤46, m is an integer, 27≤n≤68, n is aninteger. The base matrix is permuted based on the lifting factor Z, toobtain the LDPC matrix.

It should be noted that, Z=26, a=13, and the matrix shown in FIG. 3b -7Aand FIG. 3b -7B are merely used as an example for description herein,and the present application is not limited thereto. It may be understoodthat different lifting factors indicate different base matrices.

In one embodiment, a correspondence between a lifting factor and a basematrix may be shown in Table 5, and a base matrix index corresponding tothe lifting factor is determined according to Table 5. In oneembodiment, a PCM1 may be the matrix 30 b-10 shown in FIG. 3b -1A andFIG. 3b -1B, a PCM2 may be the matrix 30 b-20 shown in FIG. 3b -2A andFIG. 3b -2B, a PCM3 may be the matrix 30 b-30 shown in FIG. 3b -3A andFIG. 3b -3B, a PCM4 may be the matrix 30 b-40 shown in FIG. 3b -4A andFIG. 3b -4B, a PCM5 may be the matrix 30 b-50 shown in FIG. 3b -5A andFIG. 3b -5B, a PCM6 may be the matrix 30 b-60 shown in FIG. 3b -6A andFIG. 3b -6B, a PCM7 may be the matrix 30 b-70 shown in FIG. 3b -7A andFIG. 3b -7B, and a PCM8 may be the matrix 30 b-80 shown in FIG. 3b -8Aand FIG. 3b -8B. This is merely an example herein, and the presentapplication is not limited thereto.

TABLE 5 Base matrix index Lifting factor Z PCM1 2 4 8 16 32 64 128 256PCM2 3 6 12 24 48 96 192 384 PCM3 5 10 20 40 80 160 320 PCM4 7 14 28 56112 224 PCM5 9 18 36 72 144 288 PCM6 11 22 44 88 176 352 PCM7 13 26 52104 208 PCM8 15 30 60 120 240

Further, in one embodiment, for the lifting factor Z, an element P_(i,j)in a row i and a column j in the base matrix corresponding to thelifting factor Z may meet the following relationship:

$P_{i,j} = \left\{ {\begin{matrix}{- 1} & {V_{i,j} = {- 1}} \\{{mod}\left( {V_{i,j},Z} \right)} & {V_{i,j} \geq 0}\end{matrix},} \right.$

V_(i,j) may represent a shift value of an element in a row i and acolumn j in a base matrix corresponding to a set to which the liftingfactor Z belongs, or a shift value of a non-zero element in a row i anda column j in a base matrix corresponding to a largest lifting factor ina set to which the lifting factor Z belongs.

For example, using that Z is 13 as an example, an element P_(i,j) in arow i and a column j in a base matrix of the LDPC matrix meets:

$P_{i,j} = \left\{ {\begin{matrix}{- 1} & {V_{i,j} = {- 1}} \\{{mod}\left( {V_{i,j},Z} \right)} & {V_{i,j} \geq 0}\end{matrix},} \right.$where

V_(i,j) represents the PCM7, and in one embodiment, a shift value of anon-zero element in a row i and a column j in the matrix 30 b-70. WhenZ=13, a modulo operation needs to be performed, by using Z=13, on theshift value V_(i,j) of the non-zero element in the row i and the columnj in the matrix 30 b-70.

It should be noted that, this is merely an example, and the presentapplication is not limited thereto.

Part 603: Encode/decode the input sequence based on the LDPC matrix.

In one embodiment, a to-be-encoded input sequence may be an informationbit sequence. In one embodiment, a to-be-decoded input sequence may be asoft value sequence of the LDPC code. For details, refer to the relateddescriptions in FIG. 5.

When the input sequence is encoded/decoded, an LDPC matrix H may beobtained by lifting the base matrix based on Z. For each non-zeroelement P_(i,j) in the base matrix, a Z×Z circulant permutation matrixh_(i,j) is determined. h_(i,j) represents a circulant permutation matrixobtained by performing a cyclic shift on an identity matrix for P_(i,j)times. The non-zero element is replaced with h_(i,j) and a zero elementin a base matrix H_(B) is replaced with a Z×Z all-zero matrix, to obtaina parity check matrix H.

In one embodiment, the base matrix of the LDPC code may be saved in amemory, and the communications apparatus obtains the LDPC matrixcorresponding to the lifting factor Z, to encode/decode the inputsequence.

In one embodiment, because there are a plurality of base matrices of theLDPC code, relatively large storage space is occupied if the basematrices are saved based on a matrix structure. The base graph of theLDPC code may alternatively be saved in a memory, and shift values ofnon-zero elements in each base matrix may be saved by row or by column,and then an LDPC matrix is obtained based on the base graph and a shiftvalue of the base matrix corresponding to the lifting factor Z.

In one embodiment, shift values of non-zero elements in each base matrixmay alternatively be saved in forms of Table 2-10, Table 2-11, and Table3-10 to Table 3-80, and are used as parameters of the LDPC matrix. Thecolumn “Row weight” in Table 2-10, Table 2-11, and Table 3-10 to Table3-80 is optional. In other words, the column “Row weight” may beoptionally saved or may not be saved. A quantity of non-zero elements ina row may be learned from columns in which the non-zero elements in therow are located, and therefore, a row weight is learned. In oneembodiment, parameter values in “columns in which non-zero elements arelocated” in Table 2-10, Table 2-11, and Table 3-10 to Table 3-80 may notbe arranged in ascending order, provided that the parameter values areindexed to the columns in which the non-zero elements are located. Inaddition, parameter values in “shift values of the non-zero elements” inTable 2-10, Table 2-11, and Table 3-10 to Table 3-80 are not necessarilyarranged in a column sequence either, provided that the parameter valuesin “shift values of the non-zero elements” are in a one-to-onecorrespondence with the parameter values in “columns in which non-zeroelements are located”. The communications apparatus may learn a row anda column that are corresponding to a shift value of a non-zero element.

In one embodiment, related parameters of the LDPC matrix may be savedwith reference to the related descriptions in FIG. 5.

In one embodiment, when the related parameters of the LDPC matrix aresaved, all rows in the matrices shown in FIG. 1 to FIG. 3a -1 and FIG.3a -2 and FIG. 3b -1A to FIG. 3b -8B, or Table 2-10, Table 2-11, andTable 3-10 to Table 3-80 may not be saved, and parameters indicated bycorresponding rows in the tables may be saved based on rows included inthe base matrix. For example, a matrix formed by rows and columnsincluded in the base matrix of the LDPC matrix described in theforegoing embodiment, or related parameters of the matrix formed by rowsand columns may be saved.

For example, if the base matrix includes a row 0 to a row 4 and a column0 to a column 26 in any one of matrices 30 b-10 to 30 b-80, a matrixformed by the row 0 to the row 4 and the column 0 to the column 26 maybe saved, and/or related parameters of a matrix formed by the row 0 tothe row 4 and the column 0 to the column 26 may be saved. For details,refer to the parameters shown in Table 3-10 to Table 3-80 and theforegoing descriptions.

If the base matrix includes a row 0 to a row (m−1) and a column 0 to acolumn (n−1) in any one of matrices 30 b-10 to 30 b-80, a matrix formedby the row 0 to the row (m−1) and the column 0 to the column (n−1) maybe saved, and/or related parameters of a matrix formed by the row 0 tothe row (m−1) and the column 0 to the column (n−1) may be saved, where5≤m≤46, m is an integer, 27≤n≤68, and n is an integer. For details,refer to the parameters shown in Table 3-10 to Table 3-80 and theforegoing descriptions.

In one embodiment, each shift value that is greater than or equal to 0and that is indicated by a position s in at least one of “columns inwhich non-zero elements are located” in any one of Table 3-10 to Table3-80 may be increased or decreased by an offset Offset_(s).

It should be noted that, this is merely an example, and the presentapplication is not limited thereto.

Using FIG. 1 as an example, after the base matrix H_(B) is determined,parity bits corresponding to a row 22 to a row 25 may be obtained firstby using the input sequence and a row 0 to a row 3 and a column 0 to acolumn 25 in the base matrix, that is, H_(core-dual). Then, a column 26is obtained based on the input sequence and the parity bitscorresponding to H_(core-dual), that is, parity bits corresponding to acolumn having a column weight of 1. Next, parity bits corresponding tothe submatrix E are obtained based on the input sequence and the paritybits corresponding to the column 22 to the column 26 and after paritybits corresponding to the submatrix D are encoded, to complete encoding.For an encoding process of the LDPC code, refer to the descriptions inthe foregoing embodiments. Details are not described herein.

In one embodiment, in a communications system, an LDPC code may beobtained after encoding by using the foregoing method. After the LDPCcode is obtained, the communications apparatus may further perform oneor more of the following operations: performing rate matching on theLDPC code; performing interleaving on the rate-matched LDPC code basedon an interleaving scheme; modulating the interleaved LDPC code based ona modulation scheme, to obtain a bit sequence X; and sending the bitsequence X.

Decoding is an inverse process of encoding, and a base matrix used in adecoding process has a same characteristic as a base matrix used in anencoding process. For the encoding process of the LDPC code, refer tothe descriptions in the foregoing embodiments. Details are not describedherein. In one embodiment, before the decoding, the communicationsapparatus may further perform one or more of the following operations:receiving a signal obtained through LDPC encoding; performingdemodulation, deinterleaving, and de-rate matching on the signal toobtain a soft value sequence of the LDPC code; and decoding the softvalue sequence of the LDPC code.

“Save” in this application may be saving the parameters in one or morememories. The one or more memories may be separately disposed, or may beintegrated into an encoder or a decoder, a processor, a chip, acommunications apparatus, or a terminal. Alternatively, some of the oneor more memories may be separately disposed, and the others may beintegrated into a decoder, a processor, a chip, a communicationsapparatus, or a terminal. A type of the memory may be any form ofstorage medium. This is not limited in this application.

Corresponding to the design of the data processing process shown in FIG.5 or FIG. 6, an embodiment of the present application further provides acorresponding communications apparatus. The communications apparatusincludes a corresponding module configured to perform each part in FIG.5 or FIG. 6. The module may be software, hardware, or a combination ofsoftware and hardware. For example, the module may include a memory, anelectronic device, an electronic component, a logic circuit, or anycombination thereof. FIG. 7 is a schematic structural diagram of acommunications apparatus 700. The apparatus 700 may be configured toimplement the methods described in the foregoing method embodiments. Fordetails, refer to the descriptions in the foregoing method embodiments.The communications apparatus 700 may be a chip, a base station, aterminal, or another network device.

The communications apparatus 700 includes one or more processors 701.The processor 701 may be a general-purpose processor, a special-purposeprocessor, or the like. For example, the processor 701 may be a basebandprocessor or a central processing unit. The baseband processor may beconfigured to process a communication protocol and communications data.The central processing unit may be configured to: control thecommunications apparatus (such as the base station, the terminal, or thechip), execute a software program, and process data of the softwareprogram.

In one embodiment, one or more modules in FIG. 7 may be implemented byone or more processors, or may be implemented by one or more processorsand memories.

In one embodiment, the communications apparatus 700 includes the one ormore processors 701, and the one or more processors 701 may implementthe foregoing encoding/decoding function. For example, thecommunications apparatus may be an encoder or a decoder. In oneembodiment, in addition to a encoding/decoding function, the processor701 may implement another function.

The communications apparatus 700 encodes/decodes an input sequence basedon an LDPC matrix. A base matrix of the LDPC matrix may be any basematrix in the foregoing examples, or a base matrix obtained bytransforming a row sequence, or a column sequence, or both a rowsequence and a column sequence relative to any base matrix listed above,or a base matrix obtained by shortening or puncturing any base matrixlisted above, or a matrix obtained by lifting any base matrix listedabove. For encoding or decoding processing, refer to the relateddescriptions in FIG. 5 and FIG. 6. Details are not described hereinagain.

In one embodiment, in a design, the processor 701 may include aninstruction 703 (sometimes also referred to as code or a program). Theinstruction may be run on the processor, so that the communicationsapparatus 700 performs the methods described in the foregoingembodiments. In one embodiment, the communications apparatus 700 mayfurther include a circuit, and the circuit may implement theencoding/decoding function in the foregoing method embodiments.

In one embodiment, in a design, the communications apparatus 700 mayinclude one or more memories 702. The one or more memories 702 store aninstruction 704. The instruction may be run on the processor, so thatthe communications apparatus 700 performs the methods described in theforegoing method embodiments.

In one embodiment, the memory may further store data. In one embodiment,the processor may also store an instruction and/or data. The processorand the memory may be separately disposed, or may be integratedtogether.

In one embodiment, “save” in the foregoing embodiment may be saving inthe memory 702, or may be saving in another peripheral memory or storagedevice.

For example, the one or more memories 702 may store a parameter relatedto the LDPC matrix listed above, for example, a parameter related to abase matrix, such as a shift value, a base graph, a matrix obtained bylifting the base graph, a row in the base matrix, a lifting factor, thebase matrix, and a matrix obtained by lifting the base matrix. Fordetails, refer to the related descriptions in FIG. 5.

In one embodiment, the communications apparatus 700 may further includea transceiver 705 and an antenna 706. The processor 701 may be referredto as a processing unit, and controls the communications apparatus (theterminal or the base station). The transceiver 505 may be referred to asa transceiver unit, a transceiver, a transceiver circuit, a transceiver,or the like, and is configured to implement a transceiver function ofthe communications apparatus by using the antenna 506.

In one embodiment, the communications apparatus 700 may further includea device configured to generate a transport block CRC, a deviceconfigured to perform code block segmentation and a CRC check, aninterleaver configured to perform interleaving, a device configured toperform rate matching, a modulator configured to perform modulationprocessing, or the like. Functions of these devices may be implementedby the one or more processors 701.

In one embodiment, the communications apparatus 700 may further includea demodulator configured to perform a demodulation operation, adeinterleaver configured to perform de-interleaving, a componentconfigured to perform de-rate matching, a device configured to performcode block concatenation and a CRC check, or the like. Functions ofthese devices may be implemented by the one or more processors 701.

FIG. 8 is a schematic diagram of a communications system 800. Thecommunications system 800 includes a communications device 80 and acommunications device 81. Information data is received and sent betweenthe communications device 80 and the communications device 81. Thecommunications device 80 and the communications device 81 may be thecommunications apparatus 700, or the communications device 80 and thecommunications device 81 each include the communications apparatus 700,and receive and send the information data. For example, thecommunications device 80 may be a terminal, and correspondingly, thecommunications device 81 may be a base station. For another example, thecommunications device 80 is a base station, and correspondingly, thecommunications device 81 may be a terminal.

A person skilled in the art may further understand that variousillustrative logical blocks (illustrative logical block) and operations(operation) that are listed in the embodiments of the presentapplication may be implemented by using electronic hardware, computersoftware, or a combination thereof. Whether the functions areimplemented by using hardware or software depends on particularapplications and a design requirement of the entire system. A personskilled in the art may use various methods to implement the describedfunctions for each particular application, but it should not beconsidered that the implementation goes beyond the scope of theembodiments of the present application.

The technologies described in this application may be implemented invarious manners. For example, these technologies may be implemented byusing hardware, software, or a combination of hardware and software.During hardware implementation, a processing unit configured to executethese technologies at a communications apparatus (such as a basestation, a terminal, a network entity, or a chip) may be implemented inone or more general-purpose processors, a digital signal processor(DSP), a digital signal processing device (DSPD), anapplication-specific integrated circuit (ASIC), a programmable logicdevice (PLD), a field-programmable gate array (FPGA), or anotherprogrammable logic apparatus, discrete gate, or transistor logic, adiscrete hardware component, or any combination thereof. Thegeneral-purpose processor may be a microprocessor. In one embodiment,the general-purpose processor may alternatively be any conventionalprocessor, controller, microcontroller, or state machine. The processormay also be implemented by a combination of computing apparatuses, suchas a digital signal processor and a microprocessor, a plurality ofmicroprocessors, one or more microprocessors with a digital signalprocessor core, or any other similar configuration.

Operations of the methods or algorithms described in the embodiments ofthe present application may be directly embedded into hardware, aninstruction executed by a processor, or a combination thereof. Thememory may be a RAM memory, a flash memory, a ROM memory, an EPROMmemory, an EEPROM memory, a register, a hard disk, a removable magneticdisk, a CD-ROM, or a storage medium of any other form in the art. Forexample, the memory may be connected to a processor, so that theprocessor may read information from the memory and write informationinto the memory. In one embodiment, the memory may alternatively beintegrated into a processor. The processor and the memory may bedisposed in an ASIC, and the ASIC may be disposed in UE. In oneembodiment, the processor and the memory may alternatively be disposedin different components of the UE.

With descriptions of the foregoing embodiments, a person skilled in theart may clearly understand that the present application may beimplemented by hardware, firmware or a combination thereof. When asoftware program is used to implement the embodiments, the embodimentsmay be implemented completely or partially in a form of a computerprogram product. The computer program product includes one or morecomputer instructions. When the computer instruction is loaded andexecuted on the computer, the procedures or functions according to theembodiments of the present application are all or partially generated.When the present application is implemented by using a software program,the foregoing functions may be stored in a computer-readable medium ortransmitted as one or more instructions or code in the computer-readablemedium. The computer may be a general-purpose computer, aspecial-purpose computer, a computer network, or another programmableapparatus. The computer instruction may be stored in a computer-readablestorage medium or may be transmitted from a computer-readable storagemedium to another computer-readable storage medium. Thecomputer-readable medium includes a computer storage medium and acommunications medium. The communications medium includes any mediumthat enables a computer program to be transmitted from one place toanother. The storage medium may be any available medium accessible to acomputer. The following provides an example but does not impose anylimitation: The computer-readable medium may include a RAM, a ROM, anEEPROM, a CD-ROM, or another optical disc storage, a magnetic diskstorage medium, or another magnetic storage device, or any other mediumthat can carry or store expected program code in a form of aninstruction or a data structure and is accessible to a computer. Inaddition, any connection may be appropriately defined as acomputer-readable medium. For example, if software is transmitted from awebsite, a server, or another remote source by using a coaxial cable, anoptical fiber/cable, a twisted pair, a digital subscriber line (DSL) orwireless technologies such as infrared ray, radio and microwave, and thecoaxial cable, optical fiber/cable, twisted pair, DSL or wirelesstechnologies such as infrared ray, radio, and microwave are included inthe definition of the medium to which they belong. For example, a diskand a disc used by the present application include a compact disc (CD),a laser disc, an optical disc, a digital versatile disc (DVD), a floppydisk, and a Blu-ray disc. The disk usually copies data by a magneticmeans, and the disc copies data optically by a laser means. Theforegoing combination should also be included in the protection scope ofthe computer-readable medium.

It should be noted that “/” in this application indicates and/or, forexample, “encoding/decoding (encoding and/or decoding)” means encoding,decoding, or encoding and decoding.

In summary, what is described above is merely example embodiments of thetechnical solutions of the present application, but is not intended tolimit the protection scope of the present application. Any modification,equivalent replacement, or improvement made without departing from thespirit and principle of the present application shall fall within theprotection scope of the present application.

What is claimed is:
 1. An encoding method comprising: encoding an inputsequence by using a low density parity check (LDPC) matrix, wherein theLDPC matrix is obtained based on a lifting factor Z and a base matrix,and the base matrix comprises a row 0 to a row 4 and a column 0 to acolumn 26 in one of the following matrices: 30 b-10, 30 b-20, 30 b-30,30 b-40, 30 b-50, 30 b-60, 30 b-70, and 30 b-80, or the base matrixcomprises a row 0 to a row 4 and some of a column 0 to a column 26 inone of the following matrices: 30 b-10, 30 b-20, 30 b-30, 30 b-40, 30b-50, 30 b-60, 30 b-70, and 30 b-80.
 2. The method according to claim 1,wherein the base matrix further comprises the row 0 to a row (m−1) andthe column 0 to a column (n−1) in one of the following matrices: 30b-10, 30 b-20, 30 b-30, 30 b-40, 30 b-50, 30 b-60, 30 b-70, and 30 b-80,wherein 5≤m≤46, and 27≤n≤68.
 3. The method according to claim 1, whereinthe lifting factor z=a×2^(j), 0≤j<7, and a∈{2, 3, 5, 7, 9, 11, 13, 15};and if a=2, the base matrix comprises a row 0 to a row 4 and a column 0to a column 26 in the matrix 30 b-10, or the base matrix comprises a row0 to a row 4 and some of a column 0 to a column 26 in the matrix 30b-10; or if a=3, the base matrix comprises a row 0 to a row 4 and acolumn 0 to a column 26 in the matrix 30 b-20, or the base matrixcomprises a row 0 to a row 4 and some of a column 0 to a column 26 inthe matrix 30 b-20; or if a=5, the base matrix comprises a row 0 to arow 4 and a column 0 to a column 26 in the matrix 30 b-30, or the basematrix comprises a row 0 to a row 4 and some of a column 0 to a column26 in the matrix 30 b-30; or if a=7, the base matrix comprises a row 0to a row 4 and a column 0 to a column 26 in the matrix 30 b-40, or thebase matrix comprises a row 0 to a row 4 and some of a column 0 to acolumn 26 in the matrix 30 b-40; or if a=9, the base matrix comprises arow 0 to a row 4 and a column 0 to a column 26 in the matrix 30 b-50, orthe base matrix comprises a row 0 to a row 4 and some of a column 0 to acolumn 26 in the matrix 30 b-50; or if a=11, the base matrix comprises arow 0 to a row 4 and a column 0 to a column 26 in the matrix 30 b-60, orthe base matrix comprises a row 0 to a row 4 and some of a column 0 to acolumn 26 in the matrix 30 b-60; or if a=13, the base matrix comprises arow 0 to a row 4 and a column 0 to a column 26 in the matrix 30 b-70, orthe base matrix comprises a row 0 to a row 4 and some of a column 0 to acolumn 26 in the matrix 30 b-70; or if a=15, the base matrix comprises arow 0 to a row 4 and a column 0 to a column 26 in the matrix 30 b-80, orthe base matrix comprises a row 0 to a row 4 and some of a column 0 to acolumn 26 in the matrix 30 b-80.
 4. The method according to claim 3,wherein if a=2, the base matrix further comprises the row 0 to a row(m−1) and the column 0 to a column (n−1) in the matrix 30 b-10, wherein5≤m≤46 and 27≤n≤68; or if a=3, the base matrix further comprises the row0 to a row (m−1) and the column 0 to a column (n−1) in the matrix 30b-20 1, wherein 5≤m≤46 and 27≤n≤68; or if a=5, the base matrix furthercomprises the row 0 to a row (m−1) and the column 0 to a column (n−1) inthe matrix 30 b-30, wherein 5≤m≤46 and 27≤n≤68; or if a=7, the basematrix further comprises the row 0 to a row (m−1) and the column 0 to acolumn (n−1) in the matrix 30 b-40, wherein 5≤m≤46 and 27≤n≤68; or ifa=9, the base matrix further comprises the row 0 to a row (m−1) and thecolumn 0 to a column (n−1) in the matrix 30 b-50, wherein 5≤m≤46 and27≤n≤68; or if a=11, the base matrix further comprises the row 0 to arow (m−1) and the column 0 to a column (n−1) in the matrix 30 b-60,wherein 5≤m≤46 and 27≤n≤68; or if a=13, the base matrix furthercomprises the row 0 to a row (m−1) and the column 0 to a column (n−1) inthe matrix 30 b-70, wherein 5≤m≤46 and 27≤n≤68; or if a=15, the basematrix further comprises the row 0 to a row (m−1) and the column 0 to acolumn (n−1) in the matrix 30 b-80, wherein 5≤m≤46 and 27≤n≤68.
 5. Themethod according to claim 1, wherein the LDPC matrix is obtained basedon the lifting factor Z and a matrix Hs that is obtained by compensatingthe base matrix, wherein the matrix Hs is obtained by increasing ordecreasing, by an offset Offset_(s), each shift value that is greaterthan or equal to 0 and that corresponds to an element in at least onecolumn s in the base matrix, and the offset Offset_(s) is an integergreater than or equal to 0, and 0≤s<23.
 6. The method according claim 5,wherein the LDPC matrix is obtained based on the lifting factor Z and amatrix that is obtained by performing row switching, or columnswitching, or row switching and column switching on the base matrix orthe compensation matrix Hs of the base matrix.
 7. A decoding methodcomprising: decoding an input sequence by using a low density paritycheck (LDPC) matrix, wherein the LDPC matrix is obtained based on alifting factor Z and a base matrix, and the base matrix comprises a row0 to a row 4 and a column 0 to a column 26 in one of the followingmatrices: 30 b-10, 30 b-20, 30 b-30, 30 b-40, 30 b-50, 30 b-60, 30 b-70,and 30 b-80, or the base matrix comprises a row 0 to a row 4 and some ofa column 0 to a column 26 in one of the following matrices: 30 b-10, 30b-20, 30 b-30, 30 b-40, 30 b-50, 30 b-60, 30 b-70, and 30 b-80.
 8. Themethod according to claim 7, wherein the base matrix further comprisesthe row 0 to a row (m−1) and the column 0 to a column (n−1) in one ofthe following matrices: 30 b-10, 30 b-20, 30 b-30, 30 b-40, 30 b-50, 30b-60, 30 b-70, and 30 b-80, wherein 5 m≤46, and 27≤n≤68.
 9. The methodaccording to claim 7, wherein the lifting factor z=a×2^(j), 0≤j<7, anda∈{2, 3, 5, 7, 9, 11, 13, 15}; and if a=2, the base matrix comprises arow 0 to a row 4 and a column 0 to a column 26 in the matrix 30 b-10, orthe base matrix comprises a row 0 to a row 4 and some of a column 0 to acolumn 26 in the matrix 30 b-10; or if a=3, the base matrix comprises arow 0 to a row 4 and a column 0 to a column 26 in the matrix 30 b-20, orthe base matrix comprises a row 0 to a row 4 and some of a column 0 to acolumn 26 in the matrix 30 b-20; or if a=5, the base matrix comprises arow 0 to a row 4 and a column 0 to a column 26 in the matrix 30 b-30, orthe base matrix comprises a row 0 to a row 4 and some of a column 0 to acolumn 26 in the matrix 30 b-30; or if a=7, the base matrix comprises arow 0 to a row 4 and a column 0 to a column 26 in the matrix 30 b-40, orthe base matrix comprises a row 0 to a row 4 and some of a column 0 to acolumn 26 in the matrix 30 b-40; or if a=9, the base matrix comprises arow 0 to a row 4 and a column 0 to a column 26 in the matrix 30 b-50, orthe base matrix comprises a row 0 to a row 4 and some of a column 0 to acolumn 26 in the matrix 30 b-50; or if a=11, the base matrix comprises arow 0 to a row 4 and a column 0 to a column 26 in the matrix 30 b-60, orthe base matrix comprises a row 0 to a row 4 and some of a column 0 to acolumn 26 in the matrix 30 b-60; or if a=13, the base matrix comprises arow 0 to a row 4 and a column 0 to a column 26 in the matrix 30 b-70, orthe base matrix comprises a row 0 to a row 4 and some of a column 0 to acolumn 26 in the matrix 30 b-70; or if a=15, the base matrix comprises arow 0 to a row 4 and a column 0 to a column 26 in the matrix 30 b-80, orthe base matrix comprises a row 0 to a row 4 and some of a column 0 to acolumn 26 in the matrix 30 b-80.
 10. The method according to claim 9,wherein if a=2, the base matrix further comprises the row 0 to a row(m−1) and the column 0 to a column (n−1) in the matrix 30 b-10, wherein5≤m≤46 and 27≤n≤68; or if a=3, the base matrix further comprises the row0 to a row (m−1) and the column 0 to a column (n−1) in the matrix 30b-20 1, wherein 5≤m≤46 and 27≤n≤68; or if a=5, the base matrix furthercomprises the row 0 to a row (m−1) and the column 0 to a column (n−1) inthe matrix 30 b-30, wherein 5≤m≤46 and 27≤n≤68; or if a=7, the basematrix further comprises the row 0 to a row (m−1) and the column 0 to acolumn (n−1) in the matrix 30 b-40, wherein 5≤m≤46 and 27≤n≤68; or ifa=9, the base matrix further comprises the row 0 to a row (m−1) and thecolumn 0 to a column (n−1) in the matrix 30 b-50, wherein 5≤m≤46 and27≤n≤68; or if a=11, the base matrix further comprises the row 0 to arow (m−1) and the column 0 to a column (n−1) in the matrix 30 b-60,wherein 5≤m≤46 and 27≤n≤68; or if a=13, the base matrix furthercomprises the row 0 to a row (m−1) and the column 0 to a column (n−1) inthe matrix 30 b-70, wherein 5≤m≤46 and 27≤n≤68; or if a=15, the basematrix further comprises the row 0 to a row (m−1) and the column 0 to acolumn (n−1) in the matrix 30 b-80, wherein 5≤m≤46 and 27≤n≤68.
 11. Themethod according to claim 7, wherein the LDPC matrix is obtained basedon the lifting factor Z and a matrix Hs that is obtained by compensatingthe base matrix, wherein the matrix Hs is obtained by increasing ordecreasing, by an offset Offset_(s), each shift value that is greaterthan or equal to 0 and that corresponds to an element in at least onecolumn s in the base matrix, and the offset Offset_(s) is an integergreater than or equal to 0, and 0≤s<23.
 12. The method according claim11, wherein the LDPC matrix is obtained based on the lifting factor Zand a matrix that is obtained by performing row switching, or columnswitching, or row switching and column switching on the base matrix orthe compensation matrix Hs of the base matrix.
 13. A terminalcomprising: a memory having instructions stored therein; and aprocessor, wherein the instructions when executed by the processor,cause the processor to perform a method comprising: encoding an inputsequence by using a low density parity check (LDPC) matrix, wherein theLDPC matrix is obtained based on a lifting factor Z and a base matrix,and the base matrix comprises a row 0 to a row 4 and a column 0 to acolumn 26 in one of the following matrices: 30 b-10, 30 b-20, 30 b-30,30 b-40, 30 b-50, 30 b-60, 30 b-70, and 30 b-80, or the base matrixcomprises a row 0 to a row 4 and some of a column 0 to a column 26 inone of the following matrices: 30 b-10, 30 b-20, 30 b-30, 30 b-40, 30b-50, 30 b-60, 30 b-70, and 30 b-80.
 14. The terminal according to claim13, wherein the base matrix further comprises the row 0 to a row (m−1)and the column 0 to a column (n−1) in one of the following matrices: 30b-10, 30 b-20, 30 b-30, 30 b-40, 30 b-50, 30 b-60, 30 b-70, and 30 b-80,wherein 5≤m≤46, and 27≤n≤68.
 15. The terminal according to claim 13,wherein the lifting factor z=a×2^(j), 0≤j<7, and a∈{2, 3, 5, 7, 9, 11,13, 15}; and if a=2, the base matrix comprises a row 0 to a row 4 and acolumn 0 to a column 26 in the matrix 30 b-10, or the base matrixcomprises a row 0 to a row 4 and some of a column 0 to a column 26 inthe matrix 30 b-10; or if a=3, the base matrix comprises a row 0 to arow 4 and a column 0 to a column 26 in the matrix 30 b-20, or the basematrix comprises a row 0 to a row 4 and some of a column 0 to a column26 in the matrix 30 b-20; or if a=5, the base matrix comprises a row 0to a row 4 and a column 0 to a column 26 in the matrix 30 b-30, or thebase matrix comprises a row 0 to a row 4 and some of a column 0 to acolumn 26 in the matrix 30 b-30; or if a=7, the base matrix comprises arow 0 to a row 4 and a column 0 to a column 26 in the matrix 30 b-40, orthe base matrix comprises a row 0 to a row 4 and some of a column 0 to acolumn 26 in the matrix 30 b-40; or if a=9, the base matrix comprises arow 0 to a row 4 and a column 0 to a column 26 in the matrix 30 b-50, orthe base matrix comprises a row 0 to a row 4 and some of a column 0 to acolumn 26 in the matrix 30 b-50; or if a=11, the base matrix comprises arow 0 to a row 4 and a column 0 to a column 26 in the matrix 30 b-60, orthe base matrix comprises a row 0 to a row 4 and some of a column 0 to acolumn 26 in the matrix 30 b-60; or if a=13, the base matrix comprises arow 0 to a row 4 and a column 0 to a column 26 in the matrix 30 b-70, orthe base matrix comprises a row 0 to a row 4 and some of a column 0 to acolumn 26 in the matrix 30 b-70; or if a=15, the base matrix comprises arow 0 to a row 4 and a column 0 to a column 26 in the matrix 30 b-80, orthe base matrix comprises a row 0 to a row 4 and some of a column 0 to acolumn 26 in the matrix 30 b-80.
 16. The terminal according to claim 15,wherein if a=2, the base matrix further comprises the row 0 to a row(m−1) and the column 0 to a column (n−1) in the matrix 30 b-10, wherein5≤m≤46 and 27≤n≤68; or if a=3, the base matrix further comprises the row0 to a row (m−1) and the column 0 to a column (n−1) in the matrix 30b-20 1, wherein 5≤m≤46 and 27≤n≤68; or if a=5, the base matrix furthercomprises the row 0 to a row (m−1) and the column 0 to a column (n−1) inthe matrix 30 b-30, wherein 5≤m≤46 and 27≤n≤68; or if a=7, the basematrix further comprises the row 0 to a row (m−1) and the column 0 to acolumn (n−1) in the matrix 30 b-40, wherein 5≤m≤46 and 27≤n≤68; or ifa=9, the base matrix further comprises the row 0 to a row (m−1) and thecolumn 0 to a column (n−1) in the matrix 30 b-50, wherein 5≤m≤46 and27≤n≤68; or if a=11, the base matrix further comprises the row 0 to arow (m−1) and the column 0 to a column (n−1) in the matrix 30 b-60,wherein 5≤m≤46 and 27≤n≤68; or if a=13, the base matrix furthercomprises the row 0 to a row (m−1) and the column 0 to a column (n−1) inthe matrix 30 b-70, wherein 5≤m≤46 and 27≤n≤68; or if a=15, the basematrix further comprises the row 0 to a row (m−1) and the column 0 to acolumn (n−1) in the matrix 30 b-80, wherein 5≤m≤46 and 27≤n≤68.
 17. Theterminal according to claim 13, wherein the LDPC matrix is obtainedbased on the lifting factor Z and a matrix Hs that is obtained bycompensating the base matrix, wherein the matrix Hs is obtained byincreasing or decreasing, by an offset Offset_(s), each shift value thatis greater than or equal to 0 and that corresponds to an element in atleast one column s in the base matrix, and the offset Offset_(s) is aninteger greater than or equal to 0, and 0≤s<23.
 18. The terminalaccording to claim 17, wherein the LDPC matrix is obtained based on thelifting factor Z and a matrix that is obtained by performing rowswitching, or column switching, or row switching and column switching onthe base matrix or the compensation matrix Hs of the base matrix.